Developing a custom profile center that needs to sync opt-ins/outs to Salesforce, to then be propagated to Pardot.
According to this documentation:
There are multiple ways to unsubscribe a subscriber from receiving communications.
A subscriber opts out by clicking the link to the profile center included in each email. The user is unsubscribed in the Marketing Cloud and the Email Opt Out flag is checked in the CRM.
A subscriber can click a link to a custom profile center and opt in or out of specific communications.
A Salesforce user can unsubscribe or opt out a subscriber manually within the CRM.
A Marketing Cloud user can unsubscribe or opt out a subscriber manually in Marketing Cloud.
https://help.salesforce.com/articleView?id=mc_co_tracking_and_unsubscribes_faqs.htm&type=5
So, for #1 it's clear. And #3 is also ok.
But what about scenarios #2 and #4?
For #2 - If we use the LogUnSubEvent - would that update Salesforce via MC Connect?
For #4 - Do manual Unsubscribe updates in Marketing Cloud propagate to Salesforce to update the OptOut field? (Which I guess refers to the hasOptedOutOfEmail field?)
LogUnSubEvent Doc: https://developer.salesforce.com/docs/atlas.en-us.mc-apis.meta/mc-apis/unsubscribing_and_logging_an_unsubevent_with_a_logunsubevent_execute_call.htm