Gunbreaker - Leveling Question

[BiffWellington]

One reason I would consider continuing the MSQ and getting to 70 now is to have access to the level 70 poetics vendor right off the bat when Shadowbringers goes live. This would let you get a head start on gearing up your Gunbreaker for going from 70 to 80.

From what I've read, you'd still get that experience bonus you mentioned on your second job after level 60, but it would be halved. And this may change with the expansion; it might be dropped from +100% to +50% at level 70 instead.

Edit: Actually, considering with such a change they'd probably also make you get one job to 80 to get this bonus, that last part might not be all that helpful after all. Never mind that part.