Currently as it stand, if you don't renew your CFI (FIRC, Pass Rate, etc...) after 2 years you lose it completely. You would then need to do a whole new CFI and CFII checkride to get it back. If this NPRM passes, there will not be an expiration on your CFI anymore, you will never lose it completely you will just fall out of currency. Which then would require the FIRC or similar to reinstate your currency. You would not have to do a checkride to reinstate your CFI.