Darlan didn't make it to the Supreme, unfortunately - though maybe the answer is the same regardless.
Henderson's other novices (including) Constitution Hill have to be viewed differently, in the context of the Betfair Hurdle, because JP has very-often used it as a stepping-stone towards the Festival, with his brightest 2m novice prospect. The option is built into their race-planning strategy, whereas it's generally not considered by any of Henderson's other owners (perhaps because he discourages it?).
JP and Frank Berry are probably licking their lips at the prospect of getting in off 145, and conversely, Henderson is probably desperate to avoid it.
Regardless, it wouldn't be JPs modus operandum to swerve the Festival. If Jonbon was to take his chance at Newbury, he would still go to Cheltenham - win, lose or draw, imo (unless something adverse happened to rule him out).