Of course, as usual, this is my opinion. UTC hasn't actually made any proclamations about what will or won't be done in terms of the classes or what kinds of classes might be assigned in the future.
Rick > John Cowan suggested... > > > We will never come close to exceeding this limit. Essentially all new > > combining characters are either class 0 or fall into one of the 200-range > > positional classes. > > Or 9, for viramas. > > One take-home point is that there won't be any more "fixed position" > classes added for Hebrew or any other scripts. > > Rick