I don't see any problems with your scenarios. They look to be a great description of the advantages of unnamed segments and make great sense. I don't think the unnamed section before the highway split is going to catch on around me because typically we are adding the control cities in the names at split so the instruction is not simply the highway name.
As far as other scenarios go there is the classic
segment between carriageways of the split highway where the cross street changes name at the highway.
I also wonder if no name segments are useful to force prompts at street splits as well as highway splits. For instance at
this intersection, without the unnamed segment traveling south on Arundel on the Bay Rd you get no instruction when staying left, but do get a "stay to the right at Thomas Point Rd" instruction if going straight. I'm wondering whether adding the no-name segment will cause instructions (both ways) if staying on Arundel on the Bay Rd. It seems to me this is exactly the same principle as you are using on highway splits (but with instructions in both directions to consider).
Lastly, I don't understand your caveat that TTS will not read out the name of the following segment, but it does display on the client.