I didnt read all of that "newish" interview, cause it was too long and its pretty late
My impression so far is they plan to make 2 games, the second being Crusader.
As was written in that interview, Crusader set the Stronghold expectations high. I loved SH1 for its campaign, yet no campaign ever, if its not somehow "random" lasts long. Usually if you play it twice, it is enough for some time, because for a third it would be - you just played it all and know what triggers happen etc., it completely loses its "newness".
When I had Stronghold, I tried making maps work with AI lords. I couldnt do anything with it, made battles in the editor for hours. Built a castle, and sieged it immediately ... but it was lifeless without AI.
Then Crusader came and it had features I really didnt even hope for, since I considered Stronghold to be a kind of "different" rts. It was the game I played a lot for like next 3 years. Its problem was small maps, mangonels on both sides spraying death ... or shields and horse archers imbas. But overall (I didnt like music as in the first title, although it was pretty good still)
I always played Crusader with my bro for coop. I didnt have the internet back then as well. Some people just get too high stress levels when playing against people

and they dont consider it to be more fun than torture lol.
So when me and bro wanted to play SH2, we couldnt. We were forced to play SHL. But somehow SHL on our machines froze from time to time, so ... in the end there was very little SH playtime and when trying to play SHC, we couldnt connect, because of those strange ways to connect. At least back in the old win 98/xp it was done automatically.
Being forced to play against people isnt the very best thing one can do. For example, Battlefield 3 is going out. Its predecessor did not mention a thing about coop not being included, so me, bro started it up, we searched and found that there was no coop. Either play single player or play against random people with latency 150+ for infantry battles at close quarters its a waste of time and nerves. Instead of giving players normal coop mode with MP maps, they it seems consider buyers to be pirates so they dont include coop MP (only campaign - but my point - once/twice done, its boring already, no randomness) They have you log in, but thats somehow not enough, were still pirates who own the game and still cant get the part we wanted the most. I play online, but 19/20 of the time I play offline. There are certain things it is good to play vs AI (especially if it doesnt cheat, unless you "tell it" to ) For example I love flying in jets,(no word of their physics, for example if "angle of attack" tells them anything xD and this is why Im really considering if to even buy that game, since it offers very little in what Im interested, since they wont be ordering me how I want to play) they wont give that in coop campaign, and what then ? Am I satisfied, or am I free or enslaved to be forced to play online ? When I want to play, I want it to be on my terms and not into doing something that instead of having fun is a torture with latency, lag, etc.
Now back to Stronghold, from SHC we always expected to have the return of skirmish AI in various shapes and sizes
The thing is, the only appealing thing (I mean, apart from new engine, bit of gameplay etc) is the campaign. SH 1 was about the campaign first and foremost, for me at least. I had no way to play MP and my bro would just alt + F4 after Id beat his "ultimate assault"
coop in any game is a major content addition, at least adding a lot to its replayability and overall longetivity. I liked first SH, I loved the entire SP military game, but there was such a big part of the story that made me love it.
Music a very big part, Im not sure but SH was one of the first games that changed music according to situation.
I believe it is better not doing a scratch about AI for coop than doing it poorly. In that case, the campaign needs to be really "overthetop" to make up for those deficiencies that people came to expect. Yes, because people dont expect anything less that SHC was. There was a really quality ( not flawless of course but still very good ) AI for managing castle, not passive guys as in sh2 they mostly were
If youd be making SHC2 soon, I believe there should be factions, not 1 for all

SHC system was good and you had total freedom in what you want and factions are kind of restrictive in that matter

It depends if you want more authenticity or freedom
Id like really interactive AI guys, be they allies or enemies. (I bet neutral wont be an option xD) Lack of AI coop in first SH3 will be felt imo, but if another full-fledged Crusader comes out after (that is, if budget allows it, from SH3 purchases it seems

) that would be awesome
Enough of my fantasies

Lack of coop AI will be felt. No doubt, but still, campaign is something that was really good back then in SH. And actual castle building, defending, sieging

I dont claim Im satisfied. I want it all of course, but I cant do anything about it, so, lets hope its good enouh

At the same time I believe there will be people who wont buy the game, because it just doesnt have coop, end of story. My bro will likely buy only 1 piece of SH 3 for me, cause he wont buy another one for himself, because he wont play MP vs random people online or against me. With me as ally yes, but vs AI.