IMO ... the PN is likely looking for 12 new ASW helicopters to support the Type 054A/P, MILGEMs and the OPV 1900s. Had there not been issues with the T129, I think the PN would've gone ahead with the AW159 as doing so would've resulted in engine commonality with the PAA. Yes, it would've been a pricey purchase ($500-600 m), but the PN may have managed it through batch purchases and installments.
However, since it's looking the ATAK is not a factor, then the PN might (as it had with the LRMPA) look at a more daring solution. In other words, they might pick a commercially available platform (e.g., AW139), and contract a third-party to configure it into an ASW-capable solution.
Ideally, we'd select the T625 and work it into an ASW platform, and then induct a huge slew of them for utility, SAR, troop transport, etc. Basically, 120-180 helicopters across the PN, PA and PAF as well as Gov't of Pak, Rangers, FC, etc. We would then build the backbone of our attack helicopter fleet with the T629, i.e., same engine, transmission and core parts as T625.