Question:
Is there still a rank gate that prevents players from teaming up if their rankings are too far apart? Will this be based on LP or MMR?
I ask because I play the game exclusively with 2 IRL friends. Both of them being single/childless have far more free time than me. If they choose to chase ranks will I be prevented from partying with them even though our MMR may be similar but they have more LP? In the current system we avoid playing Ranked unless we're all online to prevent this issue, but is the new system going to change that?
Yes. Same ruleset as previous. You should land somewhat near each other if your MMR are about the same.