Similarily here: I would have flown ZRH-HKG-SIN-FRA (LX 777, SQ A380, LH A380), the other two would have taken SIN-HKG-ZRH back due to availabilit issues: It would have been a family vaccation connected with the pleasure of F: We would have stayed in HKG for a day and SIN for a week and I believe neither of these two places will be open by then anyway, nor do I really feel like travelling that much yet. I will just try and move everything back by a year. I'm hoping LH will bring back their A380s by then as it is the only LH plane I haven't flown in F yet on LH, but I doubt it :P First world problems...
I'll probably try to get the return via HND on the LH Codeshare op by ANA to test out their new F product (but will ask for an F Lounge access voucher for FRA).
I hear the Whiskey is quite worth a try on ANA.

Depending on how they pay out the downgrade compensation (do they pay it even if flights are later cancelled or does one need to fly?) and if they compensate by each downgraded leg no matter if LH or SQ? I might just take that net profit and book another special next year.

I did the same journey last year already but the other way around and with the stay in HKG (ZRH-SIN-HKG-FRA) with LX777, SQ A380 and LH A346. It was really great, little did I know that it would be my last journey for a while.