The Short answer to this is Yes, its insecure.
To explain, you must first understand what a Bridge is. A bridge in it's simplest definition is connecting two or more networks together. I would say this basic concept has been muddied since bridging to a layperson has been obfuscated by "All in one" devices.
What you are essential doing is mapping the external internet connections to your internal Virtual Virtual Switch for your VM(s). This leaves the connection open and vulnerable.
Let get a little more realistic. You (like the the Security conscious person you are) probably have a route/firewall (Hell if you using Wifi at a coffee shop, they have some sort of protection). Now you are taking that connection to your laptop, and bridging it to your internal VM network.
The essence of what was stated by MS is true, but if you really care you need to look at the risk involved, are attackers really going be trying to hit your external ISP route, to get into your wifi bridge connection and past your SUSE FW (You are running that right?). Mostly likely not, if there going to compromise you its through email or drive by's on connection you establish.
In the off chance you are connected directly to the External Connection, you obviously are exposed, and dealing with issue is fairly similar to the how we deal with this problem today, insert a firewall between the two. You could, if you cared, setup a virtual FW (for free or purchased) which would protect that connection, by pushing the bridged connection to the Virtual FW, and on to your internal network.