In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
The validity of Jumah is not dependent upon the Khaliph or his representative performing the Jumah Salah and Khutbah. As such, the Jumah Salah and Khutbah that is performed by the learned Ulema of today are valid.
It is a major sin to leave off Jumuah without any valid Sharih reason.
And Allah Ta’āla Knows Best
Mufti Saeed Ahmed Golaub
Islamic Solutions
Jamaica