I think the best thing at this point would be a clean slate for everyone. A new start. Here is me hoping how the new arc* will turn out:
*cue fan speculation disclaimer
Instead of having Yamato being all depressed for the next 20 or so chapters I hope something traumatic will happen to erase his memory. How? Well, an accident maybe or suicide attempt? Or better yet with him being a hero rescuing one of the girls (with reckless and suicidal abandon) and ends up in hospital. With everyone afraid to trigger some emotional trauma with Yamato, Suzuka never gets a mention during Yamato's long rehabilitation.
>Yamato remembers nothing about everyone but retains some attraction to Yui although he does not know why (the memory of suzuka is gone but the feeling remains?).
>This new Yamato, without any knowledge of his old self, is determined to carve out his own life from scratch, finds faults in himself that his old self never noticed and begins afresh almost completely changed. "Selfless, considerate, responsible" (although thankfully still slight carefree and cheery) Yamato finds an affinity to the track field and makes his fitness a purpose in life, training hard.
>Everyone is glad of Yamato's actions but are uncertain about whether or not to mention Suzuka or whether the track will trigger a memory return.
Yamato finds it strange that the 3 girls in his life (Yui, Honoka, Miki) avoid his proposals of dating despite their supportive attitudes to his rehabilitation. one of them finally caves and gives into Yamato despite feelings of betrayal against Suzuka.
>Suzuka returns.....errrr, I think I'll stop there. Anymore then I'll would have to write a fanfic XD.
Well, my idea is mine but I won't be disappointed to see the mangaka do something completely different.