Randolph West details the changes in max server memory for Standard Edition in SQL Server 2016 SP1:
The memory limit of 128GB RAM applies only to the buffer pool (the 8KB data pages that are read from disk into memory — in other words, the database itself).
For servers containing more than 128GB of physical RAM, and running SQL Server 2016 with Service Pack 1 or higher, we now have options.
Randolph has a couple good clarifications on memory limits outside the buffer pool, making this worth the read.