The game industry is notoriously bad for this. Especially on the Japanese side, where almost no source code older than the PS2 era was kept by anyone outside of a couple very meticulous companies. In HoMM's case, the code probably got lost when 3DO went poof.
So sad because my beloved random map generator went poof with them. Still, how much code could there be in an expansion? Maps, creatures, a few new heroes and items; it's not like they added a new AI or gameplay features. Hopefully, they will miraculously find it a few months from now and include it as an IAP. THAT would be worth paying for.
Weird. I was trying to use the [youtube ][ /youtube] tags to embed the previous video, does that not work anymore?
They put all kinds of trademark crap in the title. Not sure if that's why I couldn't find it by search, but I was able to find it by going to another Ubisoft game, hitting the Developer Apps button at the bottom, and scrolling all thé way to the right. This was iOS US Store just now.