For what it's worth, I was there for nearly 3 years (including when this article was written) and never saw that kind of bathroom behaviour. People seemed to follow the general unwritten rules. Conversations were rare, and where they did happen, the usual idle chatter that happens anywhere, while at the sink or waiting for a toilet to be available.

I was there during one of the peaks in staff/toilet ratios. After getting rid of all of the 2 - 3 person offices and replacing it all with open plan office, and then packing us in even tighter (What they referred to as "high density" seating arrangements), actually getting to use a toilet was an extremely frustrating experience. With such a prominent gender bias, the male bathroom was constantly occupied, and a now infamous "toilet ticket" was cut (https://www.geekwire.com/2015/amazon-employees-biggest-compl...).

Eventually they relented, and as new office floor space was opened up in new buildings, they agreed to reduce staff density and set a more practical staff:toilet ratio, along with adding in an additional toilet on every floor.

side note: What would have really helped was if staff weren't selfishly spending 5-10 minutes sitting on the toilet browsing the internet or playing games on their phones. It rarely takes that long to do the necessary.