The response from PTC support engineer Michael Bennett that resolved our problem is:
This change is a result of the SPR reported in CS309421. Any new drawing with the fix applied can be reverted back to the previous behavior using the detail option antiquate_drawing 8712672 then updating sheets. This option must be entered manually and will not autofill. I can confirm that this did apply to your creo8sample.drw and that the creo4sample.drw had additional spaces added to the 1. in order to correct the indentation of additional lines.