We've heard the phrase "up and out promotion" before. I've seen it happen especially for limited availability positions....IE new manager comes in and they have a buddy they'd love to give a promotion to, but even managers have headcount targets and can't necessarily create new Senior Engineer positions..so they find a way to force out someone currently in that position so they can give it to their friend.
For departments with many GSR engineers, in-line promotion can bring you from a 6->7->8 eventually with no tangible difference in responsibilities.
My question is during layoffs.. do you think you'd be safer as a higher paid lower GSR.. or at a higher GSR and lower on the pay scale? I know there's dept headcount reduction targets during cuts, and they can be based on X number per GSR.