Let us be honest, the only reason either of these cards were banned was because they are tech's to combat the new broken pokemon Eternatus.
Bellelba & Bryceman reduces the bench size and takes away the power of Eternatus. Mismagius allows you to be down a prize card and activate Karate belt. Both of these are viable strategies to combat the power of Eternatus.
Sorry, but I feel this is a blatant money move. To keep demand high, and their chase attacker viable, they had to ban these cards, both of which were not having a crushing impact on game play. ADP is busted in expanded, but no ban, yet these fringe cards get banned... bogus.