I can offer my own report that the frequent network disconnect/reconnect cycling problem with VMware Workstation 12.5 guests is a real problem.
Ubuntu desktops float an information box announcing the network cycling when it happens. Upon disconnect, clicking browser links fails until the network reconnects.
My guests are all using NAT.
My desktop PC running VMware Workstation 12.5 has the following configuration:
Host OS: Ubuntu 16.04.1 LTS
Host CPU: Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz
Host network physical interfaces: 2 integrated with the motherboard; only one interface is presently connected.
$ lspci | grep -i net
00:1f.6 Ethernet controller: Intel Corporation Ethernet Connection (2) I219-V (rev 31)
09:00.0 Ethernet controller: Intel Corporation I211 Gigabit Network Connection (rev 03)
Host motherboard: Gigabyte Z170X-UD5 with 64GB RAM
My most frequently used Workstation guests are running various flavors of Ubuntu (12.04 32-bit, 14.04 64-bit, 16.04 64-bit). These guests were almost all created under earlier versions of VMware Workstation, but network cycling also happens on an Ubuntu 16.04.1 LTS guest created under Workstation 12.5.
Haven't been inconvenienced by noticeable network cycling on my frequently used Windows 7 64-bit guest or my FreeNAS 9.3 (FreeBSD-based) guest. Might be happening there too, but can't confirm yet.
Network cycling didn't happen to me with VMware Workstation 12.1 on the same host when booted on Ubuntu 14.04 LTS, so this network issue appears to be new for Workstation 12.5. Web search engines pop up articles about network problems with Windows guests in years past, so perhaps it's a regression in WS 12.5.