Finally got this response from Tesla in response to an email suggesting reduced pricing for MCU1 owners:
Thank you for contacting Tesla. In reference to your request for special pricing for premium connectivity, it is not available for price reduction for any reason at this time.
Warm Regards,
Reginald M. | Tesla Support
Were you expecting a different answer?
I'm sure there won't be any preferential pricing for MCU1 owners but here's an unpopular idea, make connectivity for MCU2 more expensive (let's say for streaming services)