Hi @Leebary,
No, other players won’t see your Workshop mods in TruckersMP because mods are not supported, they will be turned off when you join a TruckersMP server. The TruckersMP only supports specific mods to ensure compatibility, such as seasonal graphic mods (autumn/winter etc.) and you can find about them in Announcements by checking release notes. Fyi, A winter mod might be available soon.