All very cloak and dagger................
I deal with elderly people regularly and I'd very often suggest that, especially if cognitive difficulties may arise, that it would be helpful if family members had access to bank accounts. When my own mother was getting on, it was an easy way to manage her finances.
Of course, there is always the possibility that a family member would clear out the account(s) but that is very rare in my experience.
Every will will set out what is to happen to the Testator's estate on their death- if the bank accounts are not mentioned, and if they are expressly joint accounts , then technically, yes, they pass outside the estate BUT Revenue expressly ask in the Inland Revenue Affidavit if there are any joint property/ accounts and why they are joint, who provided the funds etc.,etc.
So, back to the OP's post - is this a sensible approach? Doesn't it all depend on why?
It may be for the reasons set out above- it might even be to defraud Revenue but, without knowing the specifics, it is impossible to say if it is a sensible approach.
And Revenue are smart cookies. If they think there is something fishy about an estate , they can audit the file.
I've only ever had a Probate file audited once but it is not a pleasant experience even when everything is above board.
mf