Do test restores. LTO is very good but without verification some will fail at some point.

But your original bluray disk are also a backup.

The only surefire method to keep the bits readable is to continue moving them onto new media every few years. Data has a built-in recurring cost. I'd love to see a solution to that problem but I think it's unlikely. It's a least possible, though, that we'll come up with a storage medium with sufficient density and durability that'll it'll be good enough.

I don't even want to think about the hairy issues associated with keeping the bits able to be interpreted. That's a human behavior problem more than a technology problem.

LTO-7 drives read LTO-6, and will be available for quite a while.

In 2016 I've used an LTO-3 drive to restore a bunch (150 or 200) of LTO-1/2 tapes from 2000-2003, and almost all but one or two worked fine.

LTO is one of the best choices for compatibility. I remember just how awful DDS (same media soft of media as DAT) tape backups were - due to differences in head alignments, it was a real lottery as to whether any given tape could be read on a different drive than the one that wrote it.