WTF?
Augustus Gloop was intended to be, and is, a great big, round, roly-poly, fatty, flubby, bubbly, big bouncy bunter who got that way because he continually stuffs his fat fucking face with chocolate. It's a cautionary tale, the whole book is. Please don't mess with it.
Some people are actually approving this nonsense, like children's author Andy Griffiths
Let's take some precedent from other fictional tales of great big fatty boom-booms and see if they can cast some sanity on this.
I guess the best example, and one I do not think we can change, precisely because his language was, and is, considered a sacred part of his writing, is Shakespeare.
Specifically the character of John Falstaff, of whom Prince Hal spoke lovingly:
'Why dost thou converse with that trunk of humours?'
and
'The bolting-hutch of beastliness, that swollen parcel of dropsies, that huge bombard of sack, that stuffed cloak-bag guts, that roasted Manningtree ox with pudding in his belly.'
Fantastic stuff,
Are we going to censor this so that it doesn't upset the sensibilities of an obese child?
I don't think so. The bard's words are sacred, as should Roald Dahl's be.
Anyway, if you think re-framing fat as something else is a good idea, South Park beat you to it:
Maybe instead of a costly and pointless canonical rewrite by a committee, have the character embark on the denial of reality themselves, it would be funnier, for a start.