We'll scrape it good but I assume there will still be glue "in" the concrete.
I only know enough to be dangerous, Shane.
we've only done maybe a couple dozen ceramic installs in kitchen and bath remodels, and only a few of those were over slab.
I don't know if there's anything in vinyl glue that will cause thinset glue to fail, but I highly doubt it ...and in particular what may have been "absorbed" on the molecular level
I do know one of the ceramic floors we installed over slab 15 years ago still looks dandy and in sound condition
EDIT to add
I also know every one of those slabs that had vinyl down for years was a
PITA to scrape clean.
Willy, we scraped and scrapped the old vinyl
..L.T.A.