I have ripped out many gypcrete jobs here in fl. And it is not allowed to be used here, just pour some water on it and wait and it disintegrates I don't recommend tiling over, I am a contractor and building inspector.

Some thin-set manufacturers still hold to the belief that gypsum has inherently low tensile strength and possesses weak surface layers that are prone to dusting. These manufacturers do not recommend gypsum as an underlayment for ceramic tile - especially in wet areas. Most recognize the biggest problems are posed by weakening of the gypsum by water or moisture exposure and chemical reactions between mortar and gypsum that form bond-breaking ettringite compounds.

Finally, someone with the same knowledge of Gypcrete that I'm familiar with! Gypcrete IS PROBLEMATIC to say the least

What are the best types of carpets to prevent falling and also to install in a home for a wheelchair or scooter user?
: Working on a new construction side, has concrete slab, the customer thinks they also want the slab to be coated in gypcrete...any hazards I should be aware?
: thanks
As most have already stated gypcrete is definitely to be avoided especially where wheelchairs are involved. It does not have the compressive strength and will wear underneath any soft surface product installed over it. This will produce delamination in a regular carpet product.

Your "hunch" should be right...
Though the material is well known and is a derived of epoxy.. It is recommended here (since my own work alas that served as a test on 10 000 sq m) to have that epoxy preparation before applying linoleum on concrete floorings, specially if they are "new" (not old in age and moisture evaporation) otherwise you will have sort of mole paths under the lino slightly swelling on invisible cracks...
In the case of gypcrete (does that thing still exist?) it seems that this one is getting to powder in some parts (is it a concrete floor or a wooden one?). If those parts are small in area you can give try with a syringe... But the best would be to cut properly the lino in those areas in a pattern fashion and to replace it by another in different shape or color after having treated the gypcrete....
But that's not really resolving anything, the best, being to get that gypcrete stuff "out" definitely... It can be a nice product when very well and thoroughly applied ... but usually the hygrometry variation tends to desiccate it to powder (too much heating) or it can break in granulates after some hard encounters with furniture....
If applied to soon on "fresh" concrete it doesn't stick properly, etc...