Yes, indeed. The base game and the DLCs have had loads of patches since release.
In, I think mission 3 of the original campaign, if you delay too much with your unit production and control of the map, the AI (Rogue) can get pretty big, pretty quickly, and you're in for either a whooping or a massive clean-up. :)
Also, in the random maps, a new victory condition was introduced called the 'Seals victory' in the Golden Realms DLC.
The 'mopping up' you needed to do in the original random games, where you have to annihilate every unit, could be shortcut for example.
Tom Chick @ Quarter to Three points this out here: https://www.quartertothree.com/fp/2014/10/02/golden-realms-fulfills-promise-age-wonders-iii-adds-hobbits
He gave the original game review a 3/5, but 5/5 with that DLC.
As well as adding their own campaigns and new victory conditions though, the new Necromancer class and races like Frostlings (think White walkers - Game of Thrones) and Tigrans introduced in Eternal Lords add so much more nuance to the game.
Necromancer means playing as an 'evil' character with completely different mechanics to that of a 'good' character.
I hugely enjoy the Necromancer play style, along with the powers/spells/abilities and differing mechanics that it can offer. Moreso than Dreadnaughts or pure Sorcerors, tbh. There's just something satisfying about blighting the map out and drowning the world in their own dead units.