People have been using MQTT with TLS for years[1][2][3]. Long before the company and line of printers existed. It's not really an excuse to say "well they didn't use it" -- they should have simply offered people the necessary configuration options to enable it.

[1]: https://mosquitto.org/blog/2018/05/version-1-5-released/ [2]: https://forums.raspberrypi.com/viewtopic.php?t=287326 [3]: https://esp32.com/viewtopic.php?t=9747