For the databases that default to read blocking on modified rows (e.g. SQLServer) and for applications which can be designed to support pessimistic locking for all reads, the changes reduce the level of data integrity that can be guaranteed.
As discussed in
ISPN-5876, for databases which do not default to read blocking on modified rows or applications which cannot tolerate the cost of pessimistic locking, the changes address the case where stale data may be loaded and retained until explicitly evicted or timed out.
Though the second case may be the more common, it seems like the default should be to not reduce the integrity guarantee.