Yes, but the maximum number of years' credit you can get for what you earn in 2018 is two. Under the scenario you give above you want to count the same years as both part of the SPG years and part of the combined years which of course would not be permitted.

I am not even sure that if you had 25 SPG stays from Jan 2017 through Mar 2017 and then an entirely different 40 nights from Apr 2017 through the end of the year and another 11 Marriott nights during the same period that you would get credit for a second, unique year as the rule states " If you achieved Elite status in both Rewards and SPG in the same year, you’ll receive credit for two Elite years." It says nothing about counting the status in the new program, only counting Rewards and SPG. This does not say if you achieve elite status in one of the legacy programs and in the new program you'll receive credit for two Elite years.

You could ask the Lurker for clarification but I think the wording and common sense make it clear that you would not get three years' credit nor does it appear there is any combo involving new program status that would get you a second year.