It is funny the anecdotes about different guns have nothing to do with how a Glock works. Every gun design is different and every gun will be affected differently by dry fire.
It is physics, the force goes somewhere and if it does not go into a primer, then you are putting a lot of pressure elsewhere. With centre fire, you have to do a lot of dry fire to damage anything, but, you eventually will if you do practice this every day.
Lots of dry fire in a glock will eventually damage the inside wall of the breech face. You need some serious dry fire to do this and this will happen over a very long period of time. It is a non-issue IF we had a decent warranty service repair centre in Canada, Glock most likely give you a new slide. The likelihood of you breaking the slide is very low.
Since we do not have a warranty centre, then once your slide is done, then you need a new gun.