Does corona can have an impact on visit visa decision

My brother has visitor visa of 6 month till 15th may 2021. He doesnot plans to visit now so can he apply in the coming week for 2 year visitor visa. We all have 2 year visitor visa except for him. Please guide. Or he can only apply after 15 May 2021.

Regards

He can apply at any point to renew his visit visa. The things to consider:

Although he has been previously granted a six month visa it does not automatically follow he will be granted a 2 year visit visa.
If he has not traveled to the UK then he will not have a positive history of return. This would mitigate against granting a 2 year visa.
The visa status of other family members has no bearing on wither to grant an extended visit visa.

I am applying my brother 2 year visit visa to Uk as his 6 month visa will expire in may 2021. We three his sister and parents have all 2 year visit visa. Can the corona virus impact his decision of visit visa as travel is ban. Or corona can have no effect on visit visa decisions.