It's certainly a reasonable argument, but slapping "vision" on the end of things was common for the era so I seriously doubt that was in any way borrowed. It was just something obvious/natural for the era.
Anyway, as an owner of a CreatiVision (specifically the Dick Smith Wizzard versions), I can say that the controllers are not as similar as you might think from a superficial glance, but I do agree it's easy enough to draw a path from the Intellivision and then in turn to the ColecoVision. The CreatiVision has a somewhat similar woodgrain look (though cheaper), cartridges that plug into the side, and similar action buttons (though, strangely, they're more reminiscent of the crappy Intellivision II side buttons, which themselves were cheaper versions of what was in the Master Component), etc. However, other than possibly borrowing some ideas, I just don't know if the timing would work out for out-and-out copying. Both the Intellivision and CreatiVision were born out of 1970s design sensibilities, while the ColecoVision clearly was the start of the next generation of design in the early 1980s that would mark the new generation of consoles (and computers). In other words, there was a clear effort made to distinguish the console from what came before (and Coleco did a masterful job at that, obviously) as a sort of dividing line between old/new.
I just really think most of these similarities boil down to access to the same components, access to the same design standards, and other practical concerns, with liberal use of "hey, I like that feature in console x, so let's put it in ours!" It's also important to remember what was present in the ColecoVision prototypes (there are obviously plenty of photos of what was originally intended) and how the final design deviated from that. That to me is further evidence there wasn't out-and-out copying.
In any case, it's splitting hairs at this point. Hopefully the upcoming ColecoVision book will shed some light on the inspirations for the console and the reasons behind why certain chips were chosen from the people who were there. That, along with an Intellivision book, was something I was thinking about writing after finishing the "CoCo" book (which itself uncovered many of those things for the first time for that platform), but both of those were already spoken for. I look forward to reading the findings, which hopefully will settle whether it was more on the "era-specific coincidence/inspiration" side or more on the "copying" side.
Oh, and in regards to the Telstar Arcade, I was more referring to inspiration for all the expansion options for the ColecoVision. The Telstar Arcade obviously had most of its options onboard, which was rather clumsy, while the ColecoVision obviously split them all out, including the computer.