Well my better half has been granted a Fiancee visa which kicks in on the 15th of May.Unfortunately the Philippines are still in the UK red zone because of the Brazil/Philippine variant.Hopefully the red zone will be lifted before the 6 months for the visa expires.India is taking a hammering hopefully they can contain it .
I suppose if the restrictions remain for a while, it may be a good idea to send an email requesting if it is possible to change the dates.
This link on FAQs may help you if the restrictions are not lifted in time. 6 months is a long time hopefully all will be fine for you both. Good Luck https://www.vfsglobal.com/en/Individuals/covid-19-frequently-asked-questions.html