Yeah pretty much. This is detrimental to the MSFS ecosystem as a whole, because in general, focusing on backwards compatibility with legacy systems and code will always hold you back from innovation.
There are only a handful of relatively small issues that block progress with the SDK at the moment, but the SDK is still enough to create a “study-level” aircraft, as the community likes to call it (personally not a fan of the term myself - it is far too subjective).