SECURE 2.0 Employer contribution credit

I have been reading through the text, as well as some articles on the credits. My question is specifically about the start-up plan employer contribution credit (not the admin cost credit or auto enroll etc). 

I understand it creation is through an addition /modification to §45E. 

One ASPPA article in particular says this: 

*If the employer maintained a 401(a), 403(a), SIMPLE, or SEP plan in the three taxable years immediately preceding the tax year in which the plan is adopted, the employer cannot take a deduction for the year of adoption, but is eligible for tax credits in the next four tax years.

https://www.asppa.org/news/where-credit-due-tax-credits-small-employer-plans-under-secure-20

Can some explain where that reasoning comes from? 

If I have a SIMPLE for a year, then terminate and switch to a 401(k), wouldn't I be precluded for the first three years of the 401(k)? And is there clarification somewhere about how to apply this credit if I maintained (but discontinued mid-year) a SIMPLE or one of the other types listed in the ASPPA article?

Just because I'm in year two of my new 401(k) plan, I would have still had a SIMPLE in the preceding 3 years, so how would I be an 'eligible employer'? 

I'm sure there is something simple I'm overlooking or understanding. 

Thank you for your insight!

I figured it out! just took a few minutes! 

Ha. Yes, one way to look at it is you skip a year if transitioning from SIMPLE to K.

If the 401(k) is the first ever plan, they give you the Year 0 $ for a welcome bonus.