Nothing in HRT will alter the resting position of the pelvis, as that's determined by the socket of the hip and the ways that the ligaments line up.
That said, the smaller muscles will loosen up the tension on the pelvic tilt so, if you're out of shape, it'll tilt backward a lot easier. This isn't a good thing for your back so, if you want to remain healthy, you have to do crunches which pulls your butt back under your shoulders and less sticking out like a bumper on a car.
In general, nothing related to the overall alignment of your joints or major body parts will change with HRT. These are set in the skeleton once the cartilaginous portions calcify in your late 20s and nothing short of surgery or osteoporosis will change them after that timeframe. I know there's a good bit of confusion on issues like these, peeps, but I'ma gonna have to call bunk on any changes to the hard skeleton. You've got what you've got.
The shape that you're referring to in regards to the cis woman's pelvic tilt is caused by the location of the hip socket on a pelvis with a widened illiac crest. Some girls get a little of this but, really, if you're starting HRT after puberty proper, it's unlikely that anything will change here unless the body is a bit out of shape.
Sorry to be a Debbie Downer, ladies.