As the article points out, that's not normally the case in SQL Server, it's that there are certain steps like sorting that require blocks of preallocated memory

As the article points out, that's not normally the case in SQL Server, it's that there are certain steps like sorting that require blocks of preallocated memory. SQL Server is probably like that because varchar(max) is relatively recent; I'd expect as their support for it improves that issue will go away.