That makes the most sense.
Whether they count time served or not should be a wash in terms of payroll. As others have said, if he gets to count his paid time off as his suspension he'll owe that amount back to the team. If not the team won't have to pay him. Either way the net effect on payroll will be the same. They aren't going to credit any pay recouped due to last year's games towards last year's pay, if for no other reason than it would increase the taxable income in a strong fiscal year. If Ozuna gets a full year suspension retroactive, the Braves will still get his $18MM back on the books for this year one way or the other.