Upgraded to unlimited fibre, what next....?

[#1]

I upgraded to unlimited fibre and was sent the hub one router.
The initial email said the change over would be today so what happens next?
Am I meant to receive a text or email to say when it’s been changed?
Do I just plug in my new router and it will be changed over?

[#2]

Good afternoon thank you for contacting us,

I can see that your service should activate on 28th May 2020, please keep an eye on your account as we will update you via the member centre if there are any delays.

If you have any further questions please do not hesitate to contact me further.

[#3]

Thanks for the reply.
I’m a bit confused why I would be sent an email saying it would be changed over on the 22nd May if it’s not going to be done until 28th May.

[#4]

Could be simply an openreach engineer is not now available to do the work on the original date, and it's been rescheduled.