It probably seemed like the end because it was written that way. Due to the time it takes to make animation, the writing and voice acting was completed long before Hasbro decided if they wanted a new season or not.
Rather than leave the series hanging, they said “goodbye” in a way that left it open in case Hasbro decided they wanted more. If you look at Season 4 you’ll see they did it that way for that finale, too.
This scene made it feel like the end of the series.
Thinking about it, though, maybe it’s meant as some sort of soothing brain bleach after all those dark alternate timelines, to remind you it’s a happy world despite all the things you’ve just seen :q