Upgrading from 4.2.3 to 4.3.0-beta leaves WEB-INF/lib in place

Maybe it only happens if 32-bit version was used in the past. But my last upgrade was x64 to x64. Lib folder is not removed during the upgrade. As this is a rare case, it can probably be changed to Major.

I was unable to reproduce this issue.  My test was simple. 

default installation, no additional  plug-ins. 

Test 1.

same arch 4.0.0 to 4.1.0 to 4.2.3 to 4.3.0 - no issues

Test 2

32 bit 4.1.0 to 64bit 4.2.3 to 64bit 4.3.0 - no issues

is the issue that the admin console can not be accessed at all, or just certain pages within the admin console

In my case i couldn't access main page and TLS/SSL. But by manually specifying URL i could go to other pages.