One such possibility of bus rationalisation in the future:
I suggest 23 will merge with 65 and withdrawn as 65 duplicates
DTL3 stations from Tampines to Bencoolen currently assuming that
65's load will drop significantly after DTL3 opens.
The new merged 65 will skip Bedok Reservoir Rd, Ubi Ave 2 and
Eunos Link and will ply 23's original route from Tampines Ave 1 (
via Temasek Poly), Bedok Nth Rd and PIE but will still continue to
do MacPherson Rd and Aljunied Rd as the nearest DTL3 station
(Mattar) is relatively distant. In doing so, Jalan Kolam Ayer and
Rochor Canal Rd which is currently served by 23 will be
skipped.
https://routes.one/idea/560
23 needed for Temasek Polytechnic, so no need to withdraw