Google does/did (AppEngine Java8 can't do that because they do not have any strictness) that in AppEngine, but it is hard and challenging to get right. Especially the security bits.
The Java 8 runtime removed the sandbox restrictions. Most developers hated the restrictions. I highly doubt Microsoft would go down to the path of restrictions given the history in this space.
yeah I hated it. without it I can play with AppEngine once again, it is a really good platform but many restrictions were aweful.
The last thing which would be nice if the bits to call any appengine api from custom threads (currently I copy the environment to every custom thread I do, which needs a custom ThreadFactory).
