In the first link I had to rely on google translate but I think it says in the first paragraph that both Finnish and Estonian aircrafts will be used as aggressors. For Estonias part I guess that would be your L-39 trainers?
It said that the aggressors took of from Estonia and Finland without specifying whose aircraft those were. No info on Estonian L-39 participation.
Well, that's google translate for you I guess. Thanks for sorting it out for me.