In short, some models will be retired in favour of a new system(s). Most notably, sometime this year, NAM will be retired in favour of the Rapid Refresh Forecast System (RRFS). HRRR and RAP will follow suit with RRFS v2, but there is no date on that yet. Others will be affected, but those are the big ones I thought I'd mention, especially since Windy currently uses most of those existing models.

My recommendation is to start looking into using the new RRFS model as soon as possible to avoid any ill effects from the changeover. (RRFS is not fully operational yet but is expected to be soon) Another good system to look into now is the National Blend of Models (NBM) which is already operational.

I have this and much more information available in my GitHub repo containing most publicly available weather models: https://github.com/KnownStormChaser/master-weather-model-list

It is still an active work in progress, but I am constantly updating and adding new information.