Silverlight ends in 2021 but Banks still selecting it

I remember being in the discussion at a state owned investment bank when the discussion was being had about which front-end language should be used on their new system interfaces and they choose Silverlight.

This choice was known with the full knowledge that Microsoft was going to drop it as it was not in their new architecture.

We discussed HTML5 but Silverlight was chosen, over objections.

So now 3 years on I still see them recruiting Silverlight people.

I have to ask at what point before Microsoft stops supporting Silverlight in 2021 will someone work out that they need to stop building new interfaces and go back and change out the existing ones.

Who is in charge of the technology risk side of the business??