another hosting site isn't so much a problem as whether the archaic posting format that has been used here for years can actually work elsewhere. I'm guessing it can't. At best, perhaps, it could be made into a searchable database with new posts using more current software. Understand that I am not an expert by far, and I've forgotten much of this kind of thing over recent years from lack of interest. Maybe somebody else has more information.
The fact that "feforum.com" still directs to this N54 page tells me that domain name has not expired. Also, since it does cost money to have N54 host a group, it would seem that Anthony is keeping up the payments. A quick whois I ran earlier showed the name good until 2020. Not sure if accurate. If Anthony has not kept a backup of this forum, then an N54 shutdown will lose it all. If Tapatalk decides that outdated discussion formats are a no-go, then same result.
Lots of possibilities here. If this forum has to go elsewhere, people will need to adapt to the newer phpBB posting software. At that point, it would make more sense to look at Jay's forum. I suggest seeing what develops over the next few days.