Axolotl choosing to not grow back fingers properly?

So basically around a year ago ish my axolotl lost 2 of his 4 fingers on his right hand and surprisingly he didn't even bother to grow them back but instead make the two he had bigger and longer to fill in the missing space of the two he lost.

Is he choosing to not grow them back intentionally or is it just that he doesn't need them really so nature just said nah?