In Earlier release, we have given record access via apex managed sharing. In new release we have removed the apex managed sharing, in place we have used object sharing rules. My question is during deployment the sharing rules to other sandboxes, whether the existing apex managed sharing records are deleted or not as part of sharing rules recalculation??
If the records are created via apex sharing ,then then system does not delete it as a part of recalculation .
If you had custom RowCause defined then its easy to query the table and delete those records else those record may show with rowCause Manual and it might confuse you if user has also manually shared via manual sharing button .
The only way would be to explicitly delete those records via developer console .