If this were the case I doubt they would use the excuse they use as an excuse. I think they're just mislead. Their racial narcissism is enough reason. They want to unmake the mundus and they want to be with men as little as possible. They don't want Talos to be there at any point, and if gods don't receive worship then they lose their power, or so it would seem.
There are at least two levels in the stratery of the Thalmor regarding Talos. One for those who scheme and plan, and the other for those who follow orders. The former ones know the role Talos plays in the Wheel of World and demand him removed for their plan to revert the Creation, while the latter ones only know what the former ones allow them to know.
The high ranked tell their submissive Talos is bad and fake, that mere a man cannot ascend like Auriel and the glorious ancestors of the Altmer, so his being worshipped offends the superiority of the Altmer. Then these submissive tell the same line to the Mede Empire.
We can also add a third layer between them: that Talos is a confrontation to the glory Altmeri Empire and a sting from the Doom Drum who is the enemy to them, so removing Talos leads to the total victory and domination of the Altmer to the whole Tamriel. The ones on this third layer may lie to their minions and to the Mede Empire about Talos, yet even they seem to know nothing about the Wheel and how Talos is fortifying Mundus, and they also don't know much about the true goal of the Thalmor.
The true goal of the Thalmor has confrontated much of Auriel's teaching, and it has nothing to do with the dracochrysalis. It must be hard for any common Altmer to agree on it. So the Thalmor have to trick them into cooperation and make them believe all they're doing is for the good to all Altmer.