I don't work at OSL, I'm just posting FYI. In the days before CPDLC your helpful ATCO would have informed you CTOT and any changes (some days the CTOTs are up and down like the proverbial anyway, so the one that came with the clearance is often irrelevant). When datalink was introduced pilots stopped dialling up the delivery frequency so there was little point in trying to keep pilots up to date with the changes and I've stopped even trying, so in that respect datalink is a bit of a retrograde step. I would suggest a phone call/e-mail to OSL SATCO is going to get better results than transmitting blind on PPRuNe.
Plea to pilots: If you want a better service from ATC dial up the appropriate frequency even if you are only doing datalink so that ATC can raise you to let you know of route changes, NCTOT, suspensions, airport delays etc.