1 - You speak as if peer pressure doesn't exist. The neckbeards cleared the mmorpg, which has caused a ripple-effect on the vocal community, which will parrot that the game is over. This demoralizes all players.
2 - They aren't recruiting new players like OP, they are recruiting whatever is left of other raid groups. He would have no chance to participate unless he miraculously manages to enter in a guild that is willing to group up with him for the lowbie / lower-tier stuff. If you know of such a guild, do link it here for him and he will be set - otherwise, he will be alone and without motivating in a grindy, empty leveling / gearing experience.
3 - There aren't plenty of people leveling, nor in dungeons.
4 - PvP community won't play with him. He's a new player, not suited for their premades.
5 - Guilds don't give that gear for new players, it's for their core. Newbies are automatically considered undesired dead-weights at this point.
Check the forums. People in this thread are recommending he stay away, people in god-forsaken Reddit are talking about how the game is withering in the wake of TBC rumors and Shadowlands, etc. This is not an welcoming community and game, even more when you consider that OP thinks Shadowlands is grindy: Classic is notorious for being comparatively worse in that.