Back in the day, one used to be able to purchase a simulator and a desk mounted 5-pack and yoke so that you could attain your IRL flight hours just by practicing in a video game. “Study level” comes from the depth of systems in that sim which are detailed enough you can use the game to study for the real world counterpart . Nowadays these are less available since aviation authorities would likely rather you have someone certified physically next to you when learning to fly (or so i would guess) or better yet going through an approved training program. Last i heard CFIs love flight simmers because they get to yell at the student for all the wrong stuff they learned flying virtual ones.
Personally i find “study level” a dated term since MSFS (or P3D or Xplane) is not certified to train pilots who are earning a given pilots license and properly certified sims run in the 10s of thousands of dollars (if not more). A more accurate term would “High fidelity aircraft.” It still describes the depth of simulation in that plane as one to be more accurate but leaves out any connotations that you could use it to learn the real thing (beyond cockpit familiarization)