Are you able to stream on a laptop (or phone using your wifi, not your data plan) from YouTube, Vimeo, etc?
IMO, that speed is probably at the bare minimum (especially if you have other things happening, like your phone connected to wifi, someone browsing the internet from a laptop).
The upload speed (not shown) might be a factor too. Some providers have been cutting back on upload. But, downloading requires some upload capacity for acknowledgements (not sure how Roku does it). Usually, if upload is less than 10% of download speed, it can limit what you can do with download. If you only have 1.5mbps up, that might throttle your download speed.
I'd be concerned about latency/jitter, glitches and dropped packets. I don't know if the 93% is considered good or not (at that speed, especially).
But, overall, if you can watch online videos through this 25mpbs connection now, I'd expect it to work similarly. You can always return the streaming box if it doesn't work.
"People are often amazed at how much we’ve done with the number of engineers we’ve got." (Roku CEO Anthony Wood, Austin Statesman, Oct 4, 2019). "Amazed" is one way of putting it.
We have one member here who is using Roku at ~1mbps on DSL. I believe he has it set for SD. The Roku device seems able to adapt to a wide range of speed, as long as you can accept variable quality. I think most streaming services suggest that you need around 5-9mbps for HD video, so I would get the Roku and try it out.
My own experience with a 4 Mbps DSL line was that I could generally stream anything I was interested in on YouTube or many of the various TV show and free movie apps on Roku. At the 4 Mbps level, I did encounter one instance of continually stopping and buffering one single YouTube channel. I suspect that the material there was too Hi-Res for the link.
I am now running a 25 Mbps line and have no issues of any sort with the material I stream and watch using Roku. I don't use premium channels, nor do I have a 4K TV system.