I had to look up what Ignite TV was. It appears to be a service offered by a couple of cable companies (Rogers and Shaw). From what I could find, there is no Ignite TV app for Roku devices. There appears to be an iOS and Android app, neither of which will work on a Roku. There also appears to be an "Ignite Box" that you connect to your TV via HDMI, just like any other external device.
If you use their hardware, no you won't lose any of your content available on the Roku TV itself. You would simply change to the HDMI input the Ignite device is using to view their content. From what I could find online, the Ignite box does not offer any sort of app store, so whatever it offers is all you can get with it.
Installing Ignite TV on your Roku TV should not affect the apps already installed on the Roku platform. Ignite TV is a service provided by Rogers Communications in Canada, which includes live TV channels, on-demand content, and streaming capabilities.
Roku TVs typically operate independently of specific TV service providers or streaming platforms. They have their own operating system and app ecosystem. Therefore, installing Ignite TV should not remove or affect the apps that are already installed on your Roku TV.
However, it's always a good idea to double-check with Rogers or your TV service provider for any specific instructions or recommendations regarding the installation of Ignite TV on your Roku device. They may have additional information or requirements to ensure compatibility and optimal performance.