Hey, I’m a recent KCL graduate in HPE. I think with AAB you may be fine. I believe requirements are AAA so you’re one grade short but I think should be fine. Ultimately depends on a few things, mainly how competitive applications are and then your PS. Generally what all uni’s do as well is they hand out more offers than places as they expect people to reject them or miss grades and be rejected and so with AAB I think you will be fine. On results day if you come out with those grades too I think you’ll get an offer.
For context for myself, I applied in 2019 for 2020 start. I was part of the first cohort to study the HPE degree. I applied with AAA, got an offer. I was part of the covid cohort however and so there were U-turns, oversubscribed places and heavy competition with uni’s being extra strict. I came out with A*AB, was rejected at first then given an offer. I’d assume given that there is no initial over subscription like in 2020, or hangover in 2021, places and intake are normal again and so AAB would be enough to get in.