The 2015 MBPs were the very last with removable storage[0]. The flash controller and NAND chips are soldered directly to the board on every newer MBP and are essentially non-replaceable, short of desoldering the raw NAND flash I suppose.
[0] The low tier 2016 and 2017 touchbar-less MBPs do, quixotically, have removable storage, but using a proprietary format vs the NVMe sticks in previous models. All touchbar MBPs (and M1 Macs) have soldered flash chips, and the TB-less ones were totally discontinued in 2018 IIRC.