Long Story Short - Flightsim.to made changes to their terms of service that many developers believed were poorly drafted, and possibly downright illegal and/or infringed on their IP rights.
If you want to know more about the this dispute here is a link:
As a result - a large number of well known developers including JP Logistics and also Got Friends (who do the Wilga) removed their products.
The JP Logistics C-152 mod had just short of 80,000 downloads at the time it was withdrawn so it was very popular.
The best way to obtain it is through discord as that way you will get access to updates.