Last week, Honda/Acura filed a trademark for 'MSX' specifically for use with "Vehicles; apparatus for locomotion by land, air or water; and part and fittings for all the aforesaid goods."
The original MSX trademark was filed in 2012 and doesn't expire until 2022. It could be that Honda is expanding the range of the trademark and it will continue to be used exclusively for motorcycles, as it has been used in Europe for Honda mini-bike (marketed in North America as the Grom).
Another possibility is that the trademark will be used for a baby NSX.
It's quite possible that expanding the trademark to where there's an MSX filed under different categories is what's going to make it happen. One as a motorcycle (current) and the other as an automobile.
Plus coming from the same brand it takes away from any possible conflict.
Only way I see this as a story is if Honda was to change the MSX to Grom in Europe to match NA and then use that designation for the automotive side of the company. Seems like too much effort just for a name IMO.