I think many JWs must now just think the great crowd is simply whatever JWs are alive when Armageddon comes. The whole 1935 thing is lost on them.
The ideology surrounding growth is another matter however. It's not just 2 Peter 3:9. At least when I was active, JWs habitually explained the fact Armageddon hadn't come yet on the need to preach and save as many people as possible first. Conversations like:
Oh brother, who thought we'd still be sitting here in this old system in 2002?
Not me man. But Jehovah doesn't want any to be destroyed. There are still people coming in. It's the only reason he allows this system to last a single day longer.
I heard that conversation play out literally dozens if not hundreds of times. It was cliche. Am I the only one? What are JWs going to start saying if they post 1 or 2% declines year after year? Oh yeah, Jehovah's delaying Armageddon so he can save fewer people than he would have saved a decade ago? It doesn't work.
That's even leaving aside the fact that the Watchtower has relentlessly pointed to growth as evidence of divine direction for decades.
Sustained decline over years would surely have an utterly brutal impact on JW collective psychology.