"The good news is that it is possible to opt-out, but by default LinkedIn has decided you would prefer to optin"

Isn't this in direct violation of the GDPR?

At first I said no, but… maybe. The GDPR requires a lawful basis for processing PII. The lawful bases are all fairly narrow, except for “the user said I could,” which is the “consent” lawful basis and can be applied to just about anything.

Consent must be opt-in, non-compensated or coerced, and (this is the important one) provided for each type of use. Which this does seem to violate.

It’s been a long time since I read the GDPR, and IANAL, but I think you might be right.

Unsurprisingly they are using the universal GDPR dodging backdoor: "Legitimate Interest"

Mine was off when I checked.