They are not obligated to offer a free upgrade to MCU2, unless MCU2 is required for some feature they sold you, such as FSD.
That said, I have MCU1 (with high end emmc replacement) and while it works a little slow loading maps, it does the job just fine. My wife's car cas MCU2, and the infotainment bugs out and resets just as often, though I prefer MCU1 for that since the instrument cluster doesn't go down with the main MCU. I also enjoy the fact that on MCU1 I can do some important things faster, such as turning on front or rear defroster (single click on MCU1, multiple clicks with eyes far off the road on MCU2). So no plans to pay $1500 or $2000 to upgrade to MCU2.
Tesla really should have just kept v8 or even v6 on MCU1 and just provide security patches. Older software worked faster and was more functional. This constant upgrading of old hardware to latest software written for faster and more capable software is one reason I don't want any more Teslas - the MCU ages like an iPhone, you still get the upgrades, but each upgrade makes it slower, and not all features work. MCU2 in a couple of years will be in the same spot as MCU1 is today - MCU3 is out today already, in a couple of years MCU4 will be out and MCU2 will be lacking performance to run software written for MCU4. But of course they will still force you to upgrade, so Elon can claim you have the new feature, even if it works as well as dashcam feature on MCU1 with AP2.