When will T-Mobile convert their RCS platform to the Jibe Platform (Google) for RCS?

I still have RCS provided by T-Mobile platform on my Motorola Razr Plus.  I bought the phone from T-Mobile back in June.  I turned of RCS chats a couple of months ago as RCS messages would hang while being sent out or receiving.  SMS messages would go through fine.  

I enabled RCS today to see if the platform switches to Jibe, but it was still provided by T-Mobile.  I promptly turned RCS chats off again.

I was on Mint Mobile before switching to Tmo in June.  They use the same cellular network.  However, my RCS chat platform there was Jibe.  I used an unlocked Motorola Edge phone with Mint.