I've built houses and met with framing inspectors and never heard of such a thing. Of course building codes vary but one can do almost anything when it comes to a shed in the backyard (footing or no footing).
Most code restrictions for sheds, etc. deal with distance from property line not how it's built. You as the homeowner have many options.
Not sure how you, "locked in", anything from what I see (I don't even see a row-lock...you know with concrete) and again if shed is just set (not bolted) to foundation then you taking a big risk. It's your shed man (and a nice one) but eventually it's going places if it's just sitting on the foundation.