Just to carry on from what mister 262 said,
I have posted things before about the rule and I have misinformed/incorrect on a few things. The way I see it now is that for jet 737/A320 etc flying under part 121 then the 250 hours on type is enforced. For part 135 operators there seems to be some flexibility. If you were hired as say a twin otter FO, you may later be able to move to an ATR within the same company. Remember that Susi is moving guys onto porters and the Piaggio with no time on type.
None of this is in writing. This is just what we are hearing from DDCA guys in the field. The problem is everyone can interpret the memo any way they want. Remember, this isn't a rule change its a temporary order. It's not signed into law. It was done because of the shameful use of 250 hour idiots by Lion to secure RHS pilots for virtually nothing.