I think it was just to say "hey man, this will also run on you MSX2+ computer. Now, go fish"
If Konami was still active, it prolly would've said "turbo R" too
There we cases though were the Konami ROMs actually had some additional 64Kb RAM in them, presumably to make it possible to run these games on MSX 2+ machines that only had 64 Kb of ram?