Part of the rational for the government changing the rule is that not all stocks are available with all isa providers and some don’t want to swap the whole portfolio to other providers so having more than one can overcome this problem.
I also think the other idea is some have massive portfolios and may not always want to transfer everything to a new lesser known or smaller provider so it allows people to try multiple providers.
which in Freetrade’s case could be an advantage as someone who has large portfolio with II or HL for example may not want to necessarily want to transfer it to Freetrade so they can try it before deciding on moving a portfolio
From my point of view it is good as there are UK companies I can’t get on freetrade so have to go to T212.
Also I never use Freetrade for US stocks as the fees are much higher than other providers so this will also help me with the new rules