So IChase posted a video with the devs.
Around 13-15 min, when addressing the current issue of T5 matchmaking, someone pulled a suggestion of selecting different expecting tiers for players to choose. And Sub_Octivian mentioned that captains of T5 ships would eventually grind into T7s and bully the newer newbies.
WG said in the past that they encourage people in high tiers to play lower tiers. Obviously, what sub said is not following this principle. Also how about T5 premium and ARP ships? For me, the only time to use those ships includes missions requiring low tiers and last resort of fun.
So how about putting some parameters into MM for T5, so that they will have less chance to face T7s? Come on, everyone knows MM for T5 (and T6) are not really fair., but that is the easiest way to fix the issue.