Roughly:

According to the notice of Rokycany district from 5 Oct 2021 Nr. 15131 he reneged in favor of the Czechoslovak church.

Records like this are common in church records after WW1, where people transferred to the reformed church: https://en.wikipedia.org/wiki/Czechoslovak_Hussite_Church

For genealogists it means you should search newer records not only in catholic church records, but also in Czechoslovak Hussite church records.

Sometimes people returned back to the catholic church.