There is absolutely zero reason to update your license until you either 1) need support, 2) are ready to update your site to the latest version of software. If neither of those things are true, there's no reason that you "need" to renew your license.
I have two licenses that are currently expired, one that expires in two days, and another that expires on the 10th of this month. Only one of those sites is running on XF 2.3.6. The rest are on 2.3.7. Why would I pay to update those licenses right now? Those licenses won't get updated until a new version comes out, with something that I need, and I'm ready to upgrade them.