It's hard to be sure
Momo's DF was created after Kaido was captured & taken to Punk Hazard & we know that he ate that DF after God's Valley Incident
We also saw that he had Oni Horns during his Rock Days
So if he was an Experiment, then that means he was Captured on Punk Hazard at least Twice.
And obviously, they created him for a reason, but apparently after they captured him again, all they wanted was his DF Power.
It's also interesting that he have a good relationship with CP-0, add to it the fact that Masked Guy said that they hope Vegapunk's DF is indeed a Failure, but if they are so scared of that DF's Power, why aren't they enemies of Kaido?
This is a far-fetched idea with weak hints, but it's possible that Kaido was an Experiment on Punk Hazard solely created to eat Azure Dragon DF which apparently holds a Very Powerful Ability that can change the World & only a very Powerful Being can be able to activate such Power (Kaido is Strongest Creature, while Momo's Name means Above All which Hints at his Upcoming Power-Up)
Kaido was released & sent to look for it or escaped (Whatever u prefer), he joined Rocks Pirates & finally found it & ate it on God's Valley (He & BM are the ones who betrayed Rocks Pirates, one took Azure DF & other one took Road Poneglyph from there, so Roger & Garp ended up fighting Xebec & WB alone, which is a Fair Fight)
Kaido then was captured & he refused to cooperate, so they tried to execute him multiple times to re-acquire the Fruit but they couldn't, so instead they tried to re-create his DF, but it was a Failure (Or so they were made to believe)
When WG saw that Kaido might Die, what did they do?
They sent an Army & CP-0 to capture Wano at all costs, because they must take back the Azure Dragon DF wherever it re-appears in Wano.
So the short answer is Yes, i do believe Kaido was an Experiment & his whole Story is centered around his DF which holds a yet unseen Power that only the Mightiest can wield.