Should I De-activate GSX from 2024 or how about I must act. I don't need it (GSX) in MSFS 2024 at all today.
You can try, and then re-enable GSX jetways. You might still see the message (because MSFS 2024 is installed), but you then can just reply NO to the "Continue?" question.
Without forgetting that GSX replacement Jetways can only be used on bare default airports, not add-ons or even handcrafted airports even if they are supplied as standard or as part of a World update. Everything that is not bare default MUST have the GSX replacement jetways, or you'll have parking conflicts and jetway malfunctions.