I must have miss-wrote what you read. No, when the license is not applied, Vivado won't even bother to synthesize. That seems like a logical thing.
I just downloaded another WebPack_ISE/WebPack_Vivado license and it won't begin to synthesize a small project. Complains about a missing license even though Xilinx just sent me one.
So, here's how it works out: I have the entire Vivado Design Suite on my high end, but noisy, PC. It works well AFAICT and it works with the Microblaze IP project (more or less, I'm still messing around with board files). It makes it all the way through bitgen. This installation is based on my Basys3 voucher. It is a combined license with WebPack_ISE which means I am pretty much in business subject to various restrictions such as 1 year of updates on Vivado and, of course, none for ISE (understandable).
On my normal desktop, I should have a combined license based on my Arty voucher but, somehow, I messed that up. Xilinx shows I have both products but I can't seem to find a way to recover the Arty based license. When I got the license, it wasn't clear to me that I had to also check the box for WebPack_ISE since I already had a license for that. When I installed the new license, I lost ISE and that freaked me out. So I restored a previous license and recovered ISE without really understanding what I did. But I HAD to have ISE working! My bad...
The easy solution is to buy another Arty and use the new voucher to straighten out the mess on my normal desktop. That's not a big deal and may happen when my 1 year of updates expires. In the meantime, I have everything working on my high end machine.