Based from the data I see, it did indeed changed without any mention in patch note.
- Summon by spell - summoned troop will have the same level at summoner’s magic stats.
- Summon by trait - summoned troop will have the same level as its summoner.
- Both 2 type of Summons will still capped at level 20 with collection rules in PvP/Arena/Guild War for both sides, but not capped for enemies’s side in the modes that their troops’ levels can go over 20; Raid/Invasion/Pet Rescue/Class event/Delve.
- Summon by trait by AI in those 5 modes - summoned troop will have no trait. So Infernal King in Pet Rescue will only able to resurrect once.
You can read more about it with screenshot below.