But as a cynic...this is exactly what the industry wants. .....a good reason for all your 29ers to be old hat/ obsolete toot. Then you will need to buy your bikes all over again.
The article said "at a time it seems development has stalled".....should read "a time industry desperate for a new standard to upsell to"
Yes it may "only be used in racing at present " but then so was 29ers.....look where 26 ended up....children's bikes....even if your a 5'1" female, you still get a 29er..??.!
As for rotating mass, interesting work by swiss1 (i think it was them) has proved its a bit of a misnomer. Yes more weight is bad in general, yes slower to spin up, but the flywheel effect balances the equation at the other end if the cycle. So in a non stop/ start continious effort, no real effect.
Think some recent articles about their research are on one of the cycling channels.