Sadly you are right, as much they improved visuals for the landscape wich is actually beautifull, in terms of monster its very disappointing (imo), as they re-used about 80% of the monsters you will find there (turtles,itchians,bears,pengs,spiders,bats and so on with the same textures).
I think there are only about 8-10 new monsters in the whole xpak, if i remenber correctly.
About Imhotep, yhea…they want to bring old npcs into new xpaks, same as they did with Leonidas and Sage in Ragnarok xpak, you will meet again the yellow emperor for exemple, but the main issue is the different voice actors. Imohotep new voice audio is tottaly different than you heard back in early act 2, in a strange and bad way i must say.