I'm working on Abandon Cart Journey and we want to check the status of the data extension in the decision split after the Opportunity Status in the salesforce CRM is changed, based on the change, we want to send an email. Is there a possibility to use the update contact activity in the journey to get the data from the opportunity object in the data extension? Or can we use the personalization string in the update contact activity?
I am not sure if I really get your question but, if you want to use 'real time' data in a decision split, you have to base it on 'Contact Data'. Previously, the data model with that information has to be created in Data Designer. Please have a look to this link to the documentation to understand how it works.
The update contact activity only updates information, not retrieve.