might inadvertently make their users' encrypted connections less secure and expose them to man-in-the-middle attacks,
Well no shit, given that the traffic inspection itself has to be done via a man-in-the-middle attack.
At a previous employer (large Fortune 500 company), I got roped into going to a class put on by the vendor of a proxy product.
The instructor was a very sharp fellow who flat out stated that the "HTTPS inspection" feature was a MITM attack.
Interesting thing was this company was not using the feature due to the _legal_department_ prohibiting it's use.