Canon has introduced what it calls an “accessory shoe” for the Canon EOS R3 and the recently announced Canon XF605 professional camcorder.
Yesterday, TEAC announced their first third-party accessory for the new accessory shoe which will add XLR microphone capabilities to the EOS R3 and XF605, but this is just the beginning of what we'll see for the accessory shoe in the coming months and years.
I have been told that the Canon EOS R5c will also receive this accessory shoe, which makes a lot of sense.
I have also been told that Canon may offer the accessory shoe as a paid upgrade for the Canon EOS R5. Although the source did say nothing was guaranteed, but Canon is actively talking about it.
More to come…
But on a practical level you are going to have to replace the hotshoe, the top plate and a load of electronics inside to accommodate an ‘upgrade’ so there is absolutely no way that is going to happen.
Don’t forget the announced TEAC accessory can be mounted and used on an R5 already, just via batteries and a cable.
As for retrofitting it to the R5, I don't think we can really say got hard it would be without in depth knowledge on how it interfaces with the main board. It's possible the hot shoe interface was in development at the same time as the R5 but wasn't ready.
And yes you can connect the tascam to the internal analog audio port but it kinda defeats the purpose of a high end preamp if you connect it to the cameras in built one anyway.
If the R5c is a modified R5 then Canon could definitely do it.
Also, I'm left wondering just how many R5 purchasers take video seriously enough to be interested in the "TASCAM CA-XLR2d professional XLR microphone adapter for mirrorless cameras".
My impression, which may of course be inaccurate, is that 99.9% of R5 users primarily shoot stills, and that the overheating issues had largely deterred *serious* videographers from buying the R5.
That does not mean that Canon should not offer the service.
If they have the parts and the people to install them then they really would not have much to lose.
There are several USB-C fans for a phone for about 2€, but with an red ring Canon easily call 120€ i think.
It would sure be interesting to know how many R5 owners shoot video on a level serious enough that they would be willing to pay for the upgrade.