REALIST –
It would certainly be an extra nice thing if someone would have mayim acharonim brought to the table for the guests even though it’s not his own minhag. However, I think it would be wrong to suggest that he ought to do it.
My concern is that saying so would lead us further down a slippery slope which we’re already on; one that might lead us to a place where we demand that everyone keep everyone else’s chumros in order to make Yiddishkeit monolithic, because after all, that would be most convenient. On the other hand, suggesting that someone bring Coke to the table would not especially enable chumras to proliferate this way.