No, it's not normal. The output is almost always song lyrics annotated with markup like [Bridge], [Chorus] etc. I think they're using something from OpenAI with a system prompt and/or domain-specific training on top.
It's not a pure AI output - I generated a bunch of lyrics in text (which doesn't use credits), selected the best one (obviously), padded them out with some repetition, entered a style, generated the audio a few times, selected my favourite audio, and edited the audio (poorly) by repeating a few bars of the intro to make it longer. You don't see the times it generated lyrics about X.509 certificates (even though the prompt was for them to be a valid X.509 certificate) or the times the vocals were unintelligible.
I think generative AI does work as a toy. You can ask for all sorts of insane nonsense and laugh at what the program spits out to fulfil your request. I was a paying customer of AI Dungeon 2 (before the incident where OpenAI and/or the Mormons broke it in a poor attempt to impose safety rules).
And while I'm looking at my Suno outputs list, the reason I ever bothered to use it was to see if it could render these lyrics as a ripoff of "Pure Imagination" from Willy Wonka (it cannot because it only makes actual music): https://suno.com/song/19d1a90d-9ed6-4087-94e5-89e41363726e?s...
(I'm assuming that you can open these pages just by having the links. Some of them are set to public visibility.)
Struggling to find the words but the synthetic voice directly addressing the prompt is really surreal feeling.