The looping teams are imho only really an issue in G War. The AI makes some really poor choices, but it can be unpleasantly fortunate - which can make it a problem. Yes once it starts it can win, but that has always been the case - Justice League, Goblins, Nyxbringer, Alchemist/Hellcat, Double Trolls etc.
The real problem added to the age old loop issues with empowered are the new combinations of exploding gems and Frostmage (no need to waste freeze on Mab for example) imho. For example in mono coloured base combat, say yellow vs the classic Rope Dart team, if you are frozen on yellow, you have a hard time winning. The AI feeds on masses of yellow (Ishbaala,Qilin, Rope Dart) and you will be frozen on that colour too. Your options could include cleansing (VoO), or mainly impervious, but that might negate your team power/options on winning. VoO is not available on 3 of the 6 GW days unless you want to compromise…
Frostmage also has lightning strike, so the poor AI empowered cast will often ‘bounce or slide or sky drop/explode/whatever’ into a 4 gem match when there does not seem to be one. However that’s exactly the same scenario with the Yao team meta, the AI will cast Tai Pan just about any time, and somehow make a 4 gem match from explosions etc, or sky pulls. That team does not need freeze to work perfectly, so what to do.
Vs Yao one counter is you using TPan.
In GW it’s harder to deal with as you don’t have all options necessarily available. In PVP, I can deal with it as is as I go first, with a full hand of every troop to deal with it. When DE was there pre nerf, we had nothing that worked (consistently and reliably) against it and Rope Dart team is not anything like as bad as DE where that had an absolute certain cripple on cast with similarly favourable win conditions.
If I lose - /shrug another battle. For example the Rope Dart team relies on skull damage without doomskulls… So if you use Frostmage (or maybe at times better still Assassin when going first) and skull negation you will see it lose the board, hand over skull matches and the Rope Dart team is weak to its own tactics.
The more important issue may be Essence of Evil on certain days in GW.
Incidentally something that could occur- perhaps the ‘Life’ tree could have a cleanse/bless all on 4 gem matches at say 100.