To answer your question about anti dilution, yes I believe the most recent F round investors (at £13) could have those rights - the 2019 Articles of association, section 9 gives the details, you would have to read section 9.1 about 3 times to understand it and the relevant equation , and also know if the majority investors had waived their rights, which actually we dont
As far as I understand the series F round that completed at £13 odd would have these rights (8.7 million shares out of 129 million ) , and if the next completed G funding round comes in at £8 ish nobody else from previous rounds would have these rights as they purchased at a lesser value ( £7.71? ) so haven’t been affected by the anti- dilution clause, in effect their previous holding just haven’t gone up in “value” in relation to another funding round, having said that , there will be more shares in issue.
So basically I dont think anybody will “eat the devaluation” apart from Monzo who will give more shares to the 13 pounders ( haven’t done the calculation but feel free to have a go ) from the already closed F funding round at that valuation ( Y combinator , Accel, Goodwater ++ etc ? ) , the £70-80 million funding round G that is about to close will be at the £8 ish value.
The investors that bought in at the £7.71 E funding round, and other previous rounds, and indeed in the £13 round , when they were confident enough in Monzo prospects to invest, I think will be some of the same investors in this round G and will stump up another £8 ish to increase their holding in Monzo in these “perilous” times …