Microsoft recently sent out an email to their subscribers that indicates their intention of closing Room Chat in March 2015.
They break-up and closure of rooms is split into two categories:
Windows Phone 8 & Windows Phone 8.1:
After support for Rooms ends in March 2015, you’ll still see your existing rooms on your Windows Phone 8 or 8.1. You’ll be able to view and use your room photo albums, calendars and notes on your phone. But you won’t be able to create new rooms or make membership or permissions changes to existing rooms. Additionally, you and other room members won’t be able to send any new room chat messages.
Windows 10 Technical Preview for Phones (and Small Tablets):
We’re making way for new features in Windows 10 that will help you stay in touch with the people that matter most. Once you update to Windows 10 Technical Preview for phones, rooms will no longer show up on your phone. You’ll still be able to get to your photo albums, calendars and notes, either on the web or by using other apps on your phone. You won’t be able to see your chat history or send or receive any new chats.
Once you upgrade your device to beyond Windows Phone 8.1 you will lose the ability to view any room chats you were involved in (if any) and the best recommendation is to back-up any data you wish to retain prior to upgrading to the Windows 10 Technical Preview.
To read more you can go to the FAQ.