Canon has apologised for delivery delays to some of their latest products, including the recently announced EOS R6 Mark II, RF 135mm f1.8L IS USM and Speedlite EL-5.
"Currently, we have received more orders than expected and due to the global supply of parts there is a delay in delivery. We apologise for the inconvenience caused to our customers and business partners."
Other products delayed include: EOS R5C, EOS R7, RF 400mm f2.8L IS USM and RF 800mm f5.6L IS USM,
You can read the announcement in full at: https://cweb.canon.jp/eos/info/supply-announcement2007/