I think they're clamping down on cash held in Stocks and Shares ISAs, not Cash ISAs.
As the government wants to encourage people to be invested and not hold cash, from '27 you'll only be able to add 12k in Cash ISA. They are planning to also change the limit on cash held on S&S ISAs to avoid an easy workaround for this limit
alt Hacker News
As the government wants to encourage people to be invested and not hold cash, from '27 you'll only be able to add 12k in Cash ISA. They are planning to also change the limit on cash held on S&S ISAs to avoid an easy workaround for this limit