Noone knows, but surprise release is much better than "soon™" or "few days™" announcements.
GTS at least seems to run in robust way, if not taking count their few first day server side updates (downtime), it delivers working online races and that working online platform is huge advantage for future improvements.
It's easy to get people interested i.e. Releasing few real-life tracks and and WTCC/BTCC car roster, which I'm believing at they are doing. Pushing few full series out on DLC and boom title jumps and on this point that is easy to do on over working online platform.
This can be excellent base installation for upcoming updates, but of course disappointed because there's no clear announcement what exactly we're waiting, but big names as FIA is promising for expectation of quality on updates.
Yes, true, comparing to rival title on PS4 there's nothing to shame on GTS, it's working and waiting for bugs to be fixed isn't on list, just waiting for more content (which are promised
https://www.gtplanet.net/gt-sport-players-wont-be-kept-waiting-for-dlc/) appearing.
Disappointed, bit yes, but it delivers pretty much as promised, waiting with working playable platform is not a big thing, other title players are still waiting for working game..
Personally keeping this and rival on shopping list until there's clarity of upcoming stuff considering this title and clarity of working product on other, so big disappointment if thinking at currently I don't have either of these, this title is much more ready currently and probably buying it on next week, other title may wait "few days™" for fixes before getting it.