It is illegal, at least from the point of view of the GDPR which is what these pop ups are supposed to comply with.

You could argue that the artificial delay is implemented as a way to dissuade people from declining which would fail the idea that data processing consent should be freely given (you can’t force people to opt-in).

You could also argue that even if there was a legitimate technical reason for the delay then it wouldn't be compliant because it would prove that data processing is enabled by default before the user opts-in (otherwise the delay should be on opt-in and opt-out should be instant as it's essentially a no-op).

Here are the ICO’s guidelines on the subject - you’ll see that this TrustArc trash fails on multiple points: https://ico.org.uk/for-organisations/guide-to-data-protectio...

TrustArc essentially provides "breaching the GDPR as a service" and their continued existence proves the incompetence of the data/privacy regulators in all EU countries.