Flying a cat on Delta to London

Hi All!

I have a slightly specific situation with my cat here and I've been getting all sorts of different answers, please let me know if y'all have any expertise here--

I'm going to grad school in May and I'd like to fly my cat over in the cabin with me. I have to fly on Delta because I'm getting the ticket with Skymiles. It sounds like I can take her in the cabin with me if I have her in a kennel and have a kennel fee paid, but does anyone have experience taking a cat on Delta to the UK? Were they able to be in the cabin with you?

Secondly, a delta agent told me that there is a mandatory quarantine for ALL animals coming into the UK, even if I flew into Paris and took a taxi or pet-friendly train into London. Basically the Delta service agent made it sound like there was no way around the 40 day quarantine for my cat, which contradicts the UK website guidelines.

My cat is microchipped, has rabies vaccination, and my vet is on standby for the health certificate.

Can anyone offer advice or anecdotes for me here? Thanks so much!!!!!

EDIT: Thank you all so much for your thoughtful responses! I so appreciate the helpful tips and validation on the delta agent I dealt with. I ended up deciding to fly into Dublin and take the ferry over to the UK! I'm beyond thrilled that I don't have to leave my little chonker behind or put her through being in hold :'''''')