Doubt it'll happen but having a R179 on 6th Av, 4th Av and Brighton express would pretty nice.
If I'm understanding this right, here's how each R211 order goes in term of car replacements:
-The R211S will directly replace all the R44s on the SIR, and those are expected to enter service by the summer, with R44s being pulled from service ASAP
-The base order of R211A will go to Pitkin to displace better performing R46s to CI. The first 110 R211A are meant to cover the 110 car shortage from the R32s retired in 2020, but we're almost at that number in service already. Once we get past, say, 150 cars in service, the R46s will start being retired (married pairs first). With 525 cars in the first option minus 150, we're left 375 R211s, which could replace 300 R46s. The base order is expected to be complete in about a year.
-The first option order is also R211A cars, and with 640 cars there you could replace 512 R46s, so the rest of the fleet. The second option order can then be for fleet expansion.
-The R211T will stay on the for the time being, and they'll decide whether the second option order will be open gangway or not later.