Now the ESP32 as usually delivered is not pin or voltage compatible, but surely that's not that hard of a problem. Just make an Arduino shaped board for it, and use a level shifter?
In fact this very thing seems to exist:
https://freematics.com/store/index.php?route=product/product...
The GPIO are not level shifted in the board you link.
My question here is why the weird approach? Why have two MCUs on a board, and have the one that the user interacts with be the technically inferior one?
Why not just make a better version of the ESPRIT? Just add a level shifter to it, and there you go: form factor compatible, 5V compatible, and more powerful than Arduino's not yet released project. And probably cheaper to manufacture than the two MCU design they came up with.
And yeah, you can use exactly the same IDE and API for the ESP32.
Performance must have been a non-issue, they make everything from timers for rice cookers to custom ISA smartphone SoCs. It must have been just an option that is good enough, easily available and comfortably low-tech to let to an enthusiast with an SEM in his basement.
Though does Arduino really amount to something measurable to a giant like Renesas? And I presume that Arduino plans to keep the IDE and API, so not like 99% of people would be learning anything about the details of Renesas' chips.
IDE and API won't be issues, it's just bare C/C++ and APIs are just extra standard libraries. But the popularity of Arduino and ATmega328P/ATmega32U, its expanded talent pools, etc must be somewhat tempting and potentially-vital-looking for Renesas, while also not too tempting nor threatening to make substantial changes to its operations and focus on over the counter chip sales.