Trolls in general don't go well with elves according to many lore bits, yet here we are with Darkspear and Zandalari. The zandalari even have zandalar which inhabits many differnt troll tribes. We as horde 60% elves have been around them for a full expansion. I don't think we have to really worry about that. If their grudge was that big, we would have seen something of that already by now. I think for the remaining forest trolls.. it's either stfu and join or get slaughtered by anything else. Their choice.. I don't care lol.
And ofc, if enough demand for that model it's only a matter of time. There are some frriendly tribes so it wouldn't be super hard to explain.