Not wanting to be alarmist but early symptoms of infection with HIV are flu-like (although much less severe than the coronavirus symptoms). It isn't for up to ten years later that the most serious effects i.e. AIDS emerges.
This is basically the definition of alarmist.
The government have specifically said that they are considering temporarily removing health and safety legislation re: class sizes
Cynically, I wonder if it's a backdoor way of getting parents used to larger class sizes long term. If your child was in a class of 50 last year, suddenly 35 doesn't look so bad!
I wouldn't say that the reason for changing the rules is so that parents get used to bigger class sizes, but I would doubt this governments willingness to reinstate the rules to the same levels afterwards.