The reference you quote does indeed refer to conversion of existing qualifications
when the instructor converts his/her licence and ratings to Part-FCL.
The wording is far from clear.
Actually the wording is quite clear (even if we think it is non-sensical).
For 2) and 3) below they should have put "Previous Rating: FI(A) with privileges
to instruct for IMC / IR(A)". But they didn't so these conversion requirements apply.
1) Previous Rating: FI(A) No Applied IF
Part-FCL Rating: FI(A) without instrument instruction privileges
Conversion Requirements: Hold a valid FI(A) No Applied IF
2) Previous Rating: FI(A), IR(A)
Part-FCL Rating: FI(A) with the privilege to instruct for the IR(A)
Conversion Requirements: Hold a valid FI(A), IR(A)
3) Previous Rating: FI(A), IMC rating
Part-FCL Rating: FI(A) with the privilege to instruct for the IR(Restricted) – UK only
Conversion Requirements: Hold a valid FI(A) and a valid IMC rating prior to 8 April
2014; or a UK CPL(A)/ATPL(A) issued prior to 1 July 2000. The requirement of
Part-MED,MED.A.030(g) shall not apply to the IR(R)