Different memory allocation strategy in Postgres 11?

I have a Postgres instance running on my Windows laptop for testing purposes. 

I typically configure "shared_buffers = 4096MB" on my 16GB system as sometimes when testing, it pays off to have a
biggercache. 
 

With Postgres 10 and earlier, the Postgres process(es) would only allocate that memory from the operating system when
needed.
 
So right after startup, it would only consume several hundred MB, not the entire 4GB

However with Postgres 11 I noticed that it immediately grabs the complete memory configured for shared_buffers during
startup.

It's not really a big deal, but I wonder if that is an intentional change or a result from something else? 

Regards
Thomas