Jeff Layman wrote

https://www.bbc.co.uk/news/business-56340077

Will this make any practical difference?

That remains to be seen, particularly the price of the spare parts needed
and whether they supply the smallest part that has failed or complete
sub assemblys which mean that it isnt economic to buy and swap those.

If an SMD integrated circuit goes wrong in a TV, will making the SMD
itself available make the TV "more repairable"?

Technically, yes.

How much will it cost? How much would the complete circuit board with SMD
already fitted cost? Isn't the latter what's done at present?

Not always, some like Apple refuse to supply parts to the general public.

It seems to me the manufacturers will just charge what they see fit for
the replacement part, no doubt with an exorbitant P&P to cover
"administrative costs".

Its unlikely they would get away with that.

But obviously could if they refuse to supply the smallest part that has
failed.