Hi
Whilst Apple no longer sells new Apple Watch Series 2 models, there is no need for immediate concern. Apple now sells a newer model range instead.
Apple Watch Series 2 can be updated to the latest software version, watchOS 4.x The paired iPhone needs to be an iPhone 5s or newer model, running the latest version of iOS.
Apple Watch (1st generation) models - the original range - are also still currently supported and compatible with watchOS 4.x.
If you have not yet done so, follow the instructions here to update your devices, updating your iPhone first (and starting by making a backup of your iPhone):
Beyond that, I'm afraid that no-one here can tell you anything about Apple's unannounced plans. You are not talking to Apple here - this is a user-based technical support community.