The phrase "a kind of sequel" is correct and usable in written English.
It can be used when describing a work that continues or expands upon the story or themes of a previous work, but is not a direct continuation.
Example: "The new film is a kind of sequel to the original, exploring the characters' lives years later."
Alternatives: "a sort of follow-up" or "a type of continuation".
Number 11 is billed as a "kind of sequel" to What a Carve Up!
Today, many people in the West fear we may be living through a kind of sequel.
It is fascinating to read "Nothing Was the Same" as a kind of sequel to "An Unquiet Mind".
He organized a kind of sequel to the 1963 march — this time called the Poor People's Campaign.
Almost 15 years on, Hanauer has now put together The Bitch Is Back, a kind of sequel to that book.
Heavy Weather, among Wodehouse's greatest, is a kind of sequel to Summer Lightning, though it stands alone.
That line first appeared in "Henry Fool" (1998), to which "Fay Grim" is a kind of mutant sequel.
It's hard not to see I'll Sleep as a kind of unofficial sequel to Get Carter.
The book seems a kind of affirmative sequel to the author's previous landmark volume, The Noonday Demon, published in 2001, which explored with poetic rigour the debilities of depression, in particular his own, into which he had fallen following the death of his mother, an act of planned suicide following a terminal cancer diagnosis.
Bringing Keaton back, in live action or animation, to play "old Bruce Wayne" would allow the project to be a kind of legacy sequel (think Force Awakens or Halloween) to Batman Returns.
And, yeah, within reason, I would now wonder if a kind of legacy sequel reuniting Fraser, Weisz and whomever else wanted to come along might be where this eventually heads if Universal strikes out on the fifth try (Stephen Summers deserves to get out of director's jail).
