I'm still not convinced that any of these rumors rise above standard media BS, but ...
Gronk is almost certainly the GOAT tight end, and we Pats fans have been blessed to have him on our team for most of his prime. However, all good things come to an end, sooner or later. If trading Gronk to a team where he thinks he'll be happier for the last couple-three years of his playing career needs to happen, then so be it.
Even getting "just" a 2018 2nd and 2018 3rd in trade would probably provide the Pats with enough draft capital to trade up for a top LT and still have enough left over to snag solid or better prospects at QB, LB, safety, etc. - and maybe even a TE who could rise to the level of at least Bennett or Watson.
A trade would also free up enough 2018 & 2019 cap space to make it a lot easier to extend guys like Trey Flowers and Shaq Mason.
It certainly wouldn't be the same offense without Gronk, but his absence won't kill it, either.