(Very funny tweet but on a very serious note:
HRT does not present permanence to infertility and nor does it guarantee infertility even if your natal hormones are brought down to "normal" binary levels - do not rely on HRT for this, it can absolutely backfire) https://twitter.com/Mercantoria/status/1300877521773264907

As with all things in trans healthcare - doctors fearmongering about particular parts of transition does not mean that it holds as accurate and absolute

Viable gametes can still be produced on HRT for some people
A few months off HRT can often restore lost function

Be careful

That's not to say that HRT doesn't mean a risk of (possibly even permanent, but don't quote me on that) infertility:

If you've got the means to do gametes storage I'd recommend it for the peace of mind

If you, like me, don't have the means; don't despair, there is SOME hope

This stuff is underfunded and under researched, to nobody's surprise, so it's difficult to make any clear statistical statements

But there's absolutely risks in either direction, so you need to apply your better judgement