I like to see talk about infrastructure expansion, cool beans. In the end, it's an enormous gamble that I hope pays off for them, but it's going to require consistency from players.
In other words, I hope that:
A) The influx of players continues beyond WoW's 'Shadowlands'. I mean, to each their own, of course; if one enjoys Shadowlands then more power to them! Unfortunately, though, Shadowlands is likely a huge reason for the mass exodus of players from that MMO... and therefore one of the main catalysts for the shift of many from WoW to FF. Thing is, though, humans can be fickle. If WoW's next xpac is a huge success, I'd be sad to see the droves of players go back the other way.
B) If the preceding does come to pass, and FF's player base cycles back to what it was in, say, 2019, I'd hope that the FF team handles the receding player base with more expertise than WoW did. IMVHO, Blizz kinda blew it when faced with the problem of what to do with 225 servers, but a player base that really only fills half of them to a desired capacity. "Connecting" their realms was a halfway-OK solution, but the cross-realm-zones (where people from any number of servers appeared along side you in the outside world) was not a boon for social interaction. You see those CRZ people, but you cannot trade with them, you cannot invite them to your guild, and you cannot invite them to your group easily outside of that CRZ area. This would be similar to having a Cross-Realm Visit very quietly and automatically applied to you (and removed from you) as you are moving through the world going about your business.
Anyway, yeah, after six weeks I love this game as much as I ever loved WoW. Looking forward to a bright future here and I wish all the best for this game, the production team, and the player base.