Just checking the calendar...
Well, it's not April 1.
Tried to check this out of curiosity.
An internet search using DuckDuckGo for "650D bicycle wheels" mostly returns results for 650B and 20" wheels. Checking the DDG AI bot from there returns "Sorry, no relevant information was found in our search."
I then checked for "650 D bicycle wheels" (note the space) and again DDG mostly returns info on 650B. Checking the AI bot on that page returns results stating "650D wheels, also known as 650B or 27.5-inch wheels, are a popular choice for...".
I would like to see further research in this matter, but only as a matter of curiosity.
GAJett