I finally made an account!! I was the one who peeled and removed all the black foam. There seems to be confusion about glue and self stick. Just to clarify, the tan/brown glue you are seeing in the pictures my husband posted has nothing to do with the black foam, it is residual glue from the original fiberglass installation (this glue would not come off with anything I tried, however all the fiberglass was removed). The black foam was self-stick.
That being said, the black foam is very different than the approved Mooney foam kit. The Mooney foam kit is significantly more porous and light as to not let moisture get trapped and has a very thick gooey anti-corrosive adhesive backing that fills in cracks and crevasses well. The black foam was not as porous and had a harder adhesive (on top of feeling cheap, plasticy, and heavy), so as some of you have noted it could have been the combination of the black foam with the old bumpy glue trapping moisture that caused the corrosion.
To rectify, that was the whole point of removing the fiberglass as to avoid moisture-induced corrosion on the steel frame. By replacing with alternative foam instead of the approved kit, you have the potential to create the same moisture-induced corrosion, except this time on the skins. I am a big believer in not cutting corners in aviation, it's expensive in the short-term but manufacturer's parts will save you on labor, money, and prevent damage in the long run if you intend to keep the plane for a long time.