Mwpa nomination?

Can I please check my thinking. Happy to be corrected

husband sets up life assurance under MWPA sole beneficiary Wife “or successor in title”

Wife dies

After her death Husband signs nomination in favour of their children for up to £5000

Husband died , value of assurance £12 000

on face of it full value of assurance outside Husbands estate as in trust

My thoughts however are as Wife or successor in title ( I take that to be her exors in her Will and therefore beneficiaries under her Will) are beneficiary of trust then the entire £12000 belongs to her estate and passes under her Will , of which the Husband is a beneficiary

Nomination irrelevant to ultimate entitlement of any proceeds

Therefore Husband’s entitlement in late Wife estate is now taxable in his hands

Any thoughts would be welcome

Many thanks