Don't tell them you're leaving until you finish consolidation... that's in your own best interest so you have a solid foundation when you return.
They could probably pay to to sit at home, reason being they're going to have to train you when you return anyway, it's not unreasonable that they don't want to do that twice (you're a lot cheaper than the instructors and the SIM time). You're not necessarily entitled to a free type rating if they don't even know if you'll return after the mob.
Some airlines keep new hires at arms length, ie you're not actually an employee until you finish training.