I think that there will probably be at least one update to the RMC ruleset to allow greater flexibility/optionality, although work has not yet begun on it (the FG ruleset development team has multiple rulesets to support, and the RMC ruleset hasn't long been released).
If support is added for different versions of RM (such as RMX), I think they would probably be released as new products, but that is just my guess.
StuartW