Bad fag packet!
First of all, you missed all the employers expenses...nat ins and so on, makes wages costs much higher than the minimum wage.
Then there is the presumption that all the people that paid to attend today would have come back again this season on a paid ticket...many wouldn't, they would have likely purchased a season pass instead.
Total true lost revenue...a couple of grand or so probably at most.
Additional actual coat to Merlin to revalidate tickets for reuse...zero, the park will be open and running on the return dates anyway.
Again, today's problems were very likely to be covid/staff related.