Well, it’s correct in many cases, but it has been reported on the forum as well that some TVs do indeed pass through full HD audio. Many TVs don’t though… 
That’s correct. Most soundbars are a compromise when it comes to sound as well as to connectivity. Only HDMI-capable AVRs act as HDMI switches as well - most soundbars don’t.
If the soundbar doesn’t support 4K video passthrough, you may consider @bmillham’s suggestion again: Connecting the Vero directly to you soundbar via TOSLINK and to your TV via HDMI (which will provide 4K video to the TV) at the same time should give you 5.1 sound (no HD audio though) via TOSLINK to your soundbar. You may have to use the “mute HDMI audio” option described in the wiki (Audio setup and information) though, so your TV doesn’t pass audio back to the soundbar via HDMI ARC. The soundbar may favor any HDMI audio over TOSLINK (but that’s just a guess).