No, it just means that Windows is warning you that they don't comply with Microsoft's
driver certification standards.
And as it is a beta
driver, one wouldn't expect it to.
There's nothing to stop you trying to use the
driver, but it may well throw up an error as in effect you are being asked by the software engineers to test their product before it's released to market.
However, you can always right-click the installer and choose Run as Administrator if you want to ignore the warning that the driver isn't signed.