I am not sure of the implementation effort required to support this change, but I note that the two version are incompatible and therefore kindly urge to update at the earliest convenience to ensure interoperability between all the popular unit frames and healing AddOns. ElvUI and Grid2 has already migrated and VuhDo is shipping this week.
like he already said, the LibClassicHealComm was removed because it was an unauthorized fork and therefore stolen code.
Azilroka from ElvUI got the license to work on the original LibHealComm and its working for classic now.
AddOns like Grid2 / Luna / VuhDo already switched to the LibHealComm and heal prediction communication between the old and new lib won't happen.