He explained that the delay was mainly because the developers focused on another project.

I understood that at that time, they did not have a good system of automatic porting of content to Source 2. From 2018 to 2020, they did not do this because, at that time, all key developers, including programmers, were involved in finishing Half-Life: Alyx before release.

Maxim GabeFollower Poletaev

However, Maxim claims Valve may have already found a way to transfer maps and skins to Source 2. Also, the studio wants to minimize all risks so that CS:GO Source 2 does not repeat CS:S's fate.

It is worth reminding that, judging by the information received from data miners, some maps have already been transferred to a new engine, which means the work does not stand still.

The excessive caution of the "valves" can be explained by the failure of such games as Artifact and Dota Underlords. So they would definitely like to avoid any problems with one of the primary children of Valve.