I think the benefits (or not) of molasses are in between and less extreme or significant than most are citing here. It's just some di- and monosaccharides, a very crude mix of sugars (mostly sucrose), residue or gunk from sugar refining, which will surely feed many types of fungi and bacteria (but likely not all the right/optimal ones). It definitely includes low levels of some nutrients, including calcium and magnesium, which could actually help if the amounts otherwise available to the plant are terribly low (better than nothing). But no matter what molasses is presumed to do - feed the microbes and/or provide some supplemental nutrients - it's just a small part of plant nutrition.
On balance, I think molasses in small amounts likely has some overall positive benefits.