A child is presumably a sentient being, and at some point in their life should gain control of their name. In fact, they do, to some large degree. There are means to change one's legal name, or one can diverge from their legal name and professionally/publicly use a completely different name.

A file format is not a sentient being. The creator's intent matters much more. If GIF had sentience and could voice a desire one way or the other, the whole discussion would be moot as it would clearly be disrespectful to intentionally mispronounce the name.