OP - EC 261/2004 never required any such thing. More importantly, under the April 2020 Guidance issued by the EC, it is quite clear that during the pandemic (without relation to whether there is a specific factual connection to the pandemic), Section 8 rebooking may well be met with a refund alone.
A simple way of saying to you that should you purchase a new ticket on your own, that you very well wind up with no compensation and no reimbursement for added expenses. If you are reimbursed, it will not be for a long time and after an extensive court fight (should you go to that length).
On the other hand, the additional expenses may well be covered in full or in part by your travel insurance. You should review the policy contract (don't rely on marketing materials or phone agents) to see if you have coverage. If you do, then you problem is solved.