Works as intended
I believe that the report is valid, but as a parity issue, since on Bedrock Edition the buckets of axolotls do show the type and age.
Does this comment help? https://www.reddit.com/r/Minecraft/comments/nck67c/comment/gy5qo2u.
Or you can see other replies on the post.
You are indeed supposed to put things like this to the feedback site. It's unlikely that most of them will be implemented though.
From the 25w05a changelog(https://www.minecraft.net/en-us/article/minecraft-snapshot-25w05a):
The Firefly Bush is found in Swamps and near Rivers