Possibly and possibly
As long as the source is available you can download and install from GITHUB - some-one may fork it and continue development or you may get an answer to an issue on a forum such as this or reddit etc.
As for security issues - remember the AV guys always play catch up with security issues - with no one maintaining it any faults are down to you to solve or work out if any newly announced vulnerabilities are applicable or fixable.
This is the world of software - if you do not want constant updates and a secure system do not buy a computer - use a programmable calculator

Even professional companies go bust after you have paid maintenance so there is no guarantees of fixes or secure systems now.
You have to evaluate your risks - if I was handling lots of financial information I would not use a free VPN on a £35 computer - I would buy into something more solid (Linux from Redhat falls under this). If I am just bothered by the odd surf in the local cafe I'm relaxed but then again I do not use a VPN for day to day work as my information is not critical - when it is I do it from home.