Lachi wrote:
I assume you want that these races are WT races in the actual season and that WT teams will participate (have to participate). In this case you either have to do it before the 31th of december or you have to fix the race participation in the table DYN_team_race additionally to changing the classification.

There are more things to consider like having riders participating in these races. But I think this has to be considered in any case, no matter when you edit the classification.
I cannot give details on these matters though.