You can go back to an Info prefix by adding a name column to the settings worksheet and putting Info below it.
The prefix comes from the XML form definition. What you're experiencing is a side effect of a recent change to the XLSForm form conversion tools that will affect newly-converted forms. It used to be that the XML root node name was set from the form name. However, that caused problems when the filename was very long, changed over time, or contained characters not valid in an XML element name. Now, the root node name is always data by default.
We've talked in the past about removing the prefix from the column headers since it is not very helpful. Now that most forms will have a data root node name, it's even less helpful and really just adds noise. We should consider again how we can do this in a way that doesn't disrupt ongoing data collection.
(FYI @Grzesiek2010 since you've been in related conversations recently)