Will I be covered under the insurance my employer is now offering for a procedure?

Hello,

I am in a confusing insurance situation. I currently purchase insurance through the marketplace because my Illinois based employer had not offered it to us in Michigan. Now they are offering it and I need to submit the paperwork to make the switch by end of day tomorrow for an October 1st coverage date.

I left my appointment with my specialist today and they scheduled me for a colonoscopy and esophagogastroduodenoscopy on Thursday of this week. Under my current insurance I am going to spend 2K+ on this procedure after I have met my deductible and coinsurance. I am 28 so these are diagnostic procedures.

One of the plans my employer offers is substantially better with a $500 deductible, so if I wait to have the procedures done I could save myself 1k+.

I am wondering if the new insurance provider will cover these procedures if I cancel my current appointment and wait until after October 1st to have it done. Is there an issue since it is a pre-existing condition? I've had continuous coverage through my current insurance provider for the past 2 years.

Thanks for any insight you can provide. I know I need the procedures done, but the doctor said it would be OK if I waited a month if needed.