I agree to the extent that labeling something as "transphobic" is a stretch when the researchers probably didn't even think about transgender people at all. Maybe "transinconsiderate" would be a more accurate label? Or Alex could have just said "this research reinforces cultural stereotypes and prejudices in ways that could cause problems for people like me sometime down the line".
On the other hand, I think it's legitimate to criticize research that has many obvious bad applications and few obvious good applications.
(Perhaps an important factor is why this research was being done in the first place? Did they build a "reconstruct what a person probably looks like from their voice" just to see if they could, or did they have some real application in mind? For instance, suppose they were working with a group of oceanographers who wanted a system to infer the characteristics of orcas from their whalesong as part of a project to track their migration habits, and the researchers decided to test their system on people first because it's easier and less expensive. If a project was undertaken for a good reason, but it opens the door to a lot of bad applications as an unintentional side-effect, should the researchers get a free pass on the latter?)
On the other hand, I think it's legitimate to criticize research that has many obvious bad applications and few obvious good applications.
(Perhaps an important factor is why this research was being done in the first place? Did they build a "reconstruct what a person probably looks like from their voice" just to see if they could, or did they have some real application in mind? For instance, suppose they were working with a group of oceanographers who wanted a system to infer the characteristics of orcas from their whalesong as part of a project to track their migration habits, and the researchers decided to test their system on people first because it's easier and less expensive. If a project was undertaken for a good reason, but it opens the door to a lot of bad applications as an unintentional side-effect, should the researchers get a free pass on the latter?)