As I understand it, Discovery+ is moving from 3 price levels to 2. The £3.99 subscription ("Basic"), which seems to have nothing but trashy reality programmes on it, continues, and is what those who have Discovery+ Standard will by default be put onto on their next renewal date. Unless you are paying a supplement on your Sky deal, I suspect that this is what you have.
The £6.99 "Standard package", which includes cycling, skiing, snooker and possibly some other sports, is not offered any more, and will cease to exist when the last of the monthly subscriptions expires in the next few weeks. This is where most of us are, for the next few days or weeks, as cycling fans who have not wanted to pay for 'higher profile' sports.
The "Premium" package is what they seem to think we will meekly transfer to, at £30.99, and is our opportunity to subsidise soccer, rugby, boxing, basketball, UFC (which is almost exactly what I said when I opened the email last night) and others. If you are getting all these in your Sky package, then I think Discovery + is the way that they offer those on-demand rather than as scheduled programming, so it should continue, but I don't have it so can't be sure.