People should not look at SDXC as a "memory card" but a replacement of the SuperDrive discs.
Personally I need a
CompactFlash or/and
CFexpress slot.
Many users who do not have a USB-C/TB or AirPlay projector or TV depend on full sized HDMI even when its just 2.0. Pre-historic places would have displays with VGA.
Pre-2016 MBP 15" had these I/O
Keeping MagSafe, Headphone, HDMI & SDXC slot "as is" this is how I would have done the USB of the 2016 to today's MBP
- 2016 - one TB3, one TB2 & two USB 3.1 10Gbps (introduce USB-C charger & USB-C to MagSafe cable)
- 2019 - two TB3, one TB2 & one USB 3.1 10Gbps
- 2021 - three TB4 & one USB 3.1 10Gbps
- 2024 - three TB4
A gradual transition was how Apple switched from FireWire 400 to FireWire 800. The suddent switch to USB-C ports in 2016 was too jarring.