Worth to the company or to the consumer?
It must be if they keep doing it. I'd suggest it could break-even, but I doubt companies nowadays know what that is lol
I seriously doubt Atlus cares what a vocal minority in the internet makes a drama about, even if said situation is amplified by gaming media for the sake of generating traffic to their sites.
Just a market of people that don't mind double-dipping and/or people that weren't bother to purchase the original.
If FINAL FANTASY XV proved anything, is that re-releases work, especially ones with all DLC packed into it (Royal Edition).
FFXV is a Masterclass on content updated video games living on a year, two, three beyond its release date and a new SKU.
There's also the kind of people that this take as an excuse to replay the game.
Depending on what story additions are in Vengeance, I might double-dip and replay the game. Haven't played it since the last time I touched it years ago.