The SSD in a 2015 MBP is not a SATA connection but a proprietary M.2 type connection. I think that OWC has the only SSD with the correct connector, see this
. Note where the notch is on the connector. Compared that to a standard M.2 SSD
where the notch is at a different position.
My 2009 iMac can use a regular SATA drive (hard drive or SSD), but my 2010 iMac needs the proprietary Apple drive or special adapters.
Removing the factory SSD off a 2015 MBP is not hard. There is a video tutorial on the OWC site. The procedure is much simpler than replacing the SATA drive in an iMac. Drive replacement for a later year iMac is particularly difficult.
Apple doesn't make it easy to get at the hard drive in their laptops even if it's possible to change it.
2015 MBPs are the last model that users can replace something fairly easily. All models after this year have most components soldered to the logic board. If the soldered SSD dies, how to replace it? The entire logic board? This is only economically feasible if there is warranty on the machine, otherwise a new MBP??? How "green" is that?