I think it is more a case of foresight. With young untapped potential players like Sanches, Martial, and the likes going for more and more ridiculous fees, and non top-tier stars inching up towards the transfer record... perhaps it should have been more apparent that next superstar player to be sold would be a Zidane like sale in terms of smashing the record. We sold ours 1 year early. Neymar's sale set off a chain reaction where we see obscene prices for Coutinho, Dembele, Van Dijk, etc.
But that's not the main point. We renewed our squad to CL finalist level again. Unfortunately, the biggest problem with the Pogba (and Vidal) sale is we did not manage to rebuild our midfield fully until this season. We should not have sold him without closing Matuidi first imo. Matuidi was the engine and cover we needed in that CL final second half last season. Instead we had Rincon and Lemina on the bench.
Pogba is a flop so far. No denying that. But he may not be over the long haul. Nothing wrong with string the obvious...