I don't think actual modding has changed, now what's different is that instead of modifying your own game files you will be providing mods to RAGEMP client via user_resources folder and then client will mod game for you. Also, it is said that server developers will have some kind of control over what mods you can and can't use and maybe some more things, which sounds great.
Overall, it's great improvement for everyone that is using legit mods.