Apple in 2016 removed all of the ports from its MacBook Pro models except for Thunderbolt ports, a design that persisted for years -- until today. The newly announced 2021 MacBook Pro models include an SD card slot and an HDMI port alongside three Thunderbolt ports.
As noted in Apple's technical specifications for the new machine, the HDMI port is unfortunately not top of the line -- it is an HDMI 2.0 port instead of an HDMI 2.1 port.
The HDMI 2.0 port supports a single 4K display with a resolution of up to 60Hz. HDMI 2.1 technology would have allowed the port to run a 4K display with a 120Hz refresh rate.
It's curious that Apple did not include HDMI 2.1 in the MacBook Pro models because the Apple TV 4K that was released earlier this year does have an HDMI 2.1 port.
HDMI port is only HDMI 2.0, exactly why I’d much rather have had another T4 port, what a waste. pic.twitter.com/zzUXwfGoO8 — Paul Haddad (@tapbot_paul) October 18, 2021
With the Thunderbolt 4 ports, the M1 Pro MacBook Pro models overall support up to two external displays with up to 6K resolution at 60Hz. The M1 Max MacBook Pro models support up to three external displays with up to 6K resolution and one external display with up to 4K resolution at 60Hz.
Source: Macrumors