It is not the CUJ2 update that fixes the Gmail notification issues, it is the one that was released today in SK, US, Canada, and possibly others. You will need the DUJA update.
Yes this is still an issue. The only update that i got (in Canada) was to CUJ2. I don't believe DUJA update has been made available to Canada yet.
Hoping it comes soon and resolves as others have stated.