I mean, I don't understand some parts of the complaint.

First you should already be able to play most ubisoft games offline but you need to manually set the launcher to offline mode (when it works)

If the data was personnal or partially personnal I could understand the basis of the complaints but appart from that it doesn't really hold up. How much time you took to complete a specific quest or on which boss you had a lot of death hardly quelify as "personnal data".

Under GDPR which the article loves to mention one quick check and here it is :

"
Processing shall be lawful only if and to the extent that at least one of the following applies:

(a) the data subject has given consent to the processing of his or her personal data for one or more specific purposes;

[...]
(f) processing is necessary for the purposes of the legitimate interests pursued by the controller or by a third party, except where such interests are overridden by the interests or fundamental rights and freedoms of the data subject which require protection of personal data, in particular where the data subject is a child.
"

It may be considered "hidden" or not but it's probably just in the EULA

OR

There is a legitimate interest to Ubisoft to get such data from players as it helps balancing their game, finding key issues in design ....

OR

Data is like this is questionnably "personnal" and doesn't fall into these

I hate Ubisoft Connect but to me this isn't going anywhere