Are really pinholes signs of disc rot? + Posible delamination?

I don't believe that is "rot" like that, unless you live in a zone with extreme temperatures. Those little holes are more like some impacts or damage on the top of the disk, (not the reflective side). De-lamination sounds more accurate.

But depending where is the damage it may not have any consequence on your disks:

As example: your "Mass Effect 2" or your "Horizon Zero Dawn" will be fine as the damage is in the internal part of the disk and the laser didn't read that section.

Your "Bayonetta Wii U" it's a different story... As you can see the hole is in the writable sector of the disk, so when the laser passes for that hole It will find no data written, only the acrylic.

In the last case you may start the game and get some progress, but at some point the game will freeze or crash as there is some "lost code" in that hole.

Even though the life cycle of any disk is not eternal, it could be up to 15 years or more if you take care of them. The recommendation for that is to store your disks always on the case, free of dust, never clean it with any aggressive cleaner, and keep it in a fresh and dry zone.