I believe all of the limitations you've listed above still exist with standard texting (carrier limits).
I also have not heard about an updated offering from the church.
Our ward has been using Remind (remind.com) for more than a year now.
We have a master group for the ward, and smaller groups for the RS, EQ (and even a group for the parents of the Primary Activities for Girls).
Remind has allowed us to call a "communications committee" with several members that are empowered to send messages via text.
Messages can be sent from a web browser or from a smartphone via the Remind app.
The only drawback we've seen is you can add members to the group but they have to accept the invitation -- and some don't.