I haven't heard anything about the anthology series concept since Discovery was officially announced and revealed, so I'm not sure if it amounts to anything more than a rumour.
The show is named after the ship, so I would assume it will be a continuation though. Maybe the Enterprise showing up was a setup for what they have in mind for S2, or maybe it was just some throwaway fanservice to end the season, tie in to TOS, and to bring back subscribers for next season. With any luck, they'll just skip over that little nugget and start something new. They mostly have a blank slate after wrapping everything up so quickly at the end there.