The more you call it a Reddit alternative, the more people will stop migrating over as the Reddit outrage cools down (and as much as spez can go fuck himself, he's right, it will pass). I think Mastodon had the same issue at the time of the Twitter migration, but lately it's been focussing more on the fact that good instances provide a nicer small community feel that's more reflective of the state of Twitter in 2008-2012 or so.
Advertise the community, not the drop-in replacement for another platform that will always be larger and more mainstream.
NotTheOnlyGamer