Reconnect existing Salesforce Sync Table after "Disconnect Table" was selected

Ouch. One option would be to re-create a brand new connected table. But of course you don't want to re-create all of your pipelines and relationships.  Then you would make one new pipeline, which would update your no disconnect the table from the new connected Sync Table.

You will have to look at the field that was your refresh key, which uniquely identifies the records in the old disconnected Table, and then your pipeline would know which record to act on.  You may want to consider making the key field of the disconnected table to be the refresh key that it used to have. That way when you have a pipeline running on your new connected table, it will know which record to update. You could try using the new pipeline step which does bulk trigger. So say, for example during the Sync refresh process it updates 100 records virtually at the same time. Then you could efficient the trigger a bulk trigger to update those records in the disconnected table. 

Something else to consider is if fields will be blanked out in the sync table.  Pipelines typically do not blank out target fields if the source is blank.  Thy just leave them unchnged.

So an alternative approach is see when the hourly refresh runs and set up a Saved Table to table copy form the new Sync to the old disconnected table.  Then have a pipeline run that hourly set to a munute of the hour after the Refresh is scheduled to refresh. 

Also, one more issue is if its possible that the source connected table will have records deleted which you need to delete.  There is a easy way to handle that, which I can explain if necessary.