If we agree that being trans is an illness, then yes, it makes sense to offer gamete preservation in line with other illnesses that cause fertility loss (either due to the illness itself or the treatment of the ilness).
However, if being trans is not an illness (as stated by Theresa May recently) there is no reason to offer parity of treatment.
Unless of course, two trans people in a couple are of the same birth sex, in which case they should be entitled to the same sort of fertility help as other same sex couples.
As mentioned before, this stuff is all subject to postcode lotteries anyway, regardless of cause, so I’m not sure how much difference this will make in the real world.
Pressures on the NHS mean less and less assistance is available for those struggling to conceive, so it’s more likely that help will fall for everyone, rather than significantly rise for trans people.