This old earth/new creation theory has been around since at least the 19th century. George Pember, Scofield, Watchman Nee, Chuck Missler and Larry Ollison are among those who proposed the theory. It is an explanation as to how the earth appears to be old yet Genesis says that the human race has been around for 6,000 years.
Modern geology began in the 17th century. Unbelievers used the Genesis account to cast doubt on the veracity of the Bible.
I happen to agree with it. Isaiah 45:18 says
"For thus says the LORD, who created the heavens—He is God; He formed the earth and fashioned it; He established it; He did not create it to be empty, but formed it to be inhabited: “I am the LORD, and there is no other.
Watchman Nee draws parallels with creation and the salvation of fallen man. Man was not created fallen. The earth was not created formless and empty. Man became sinful. The earth became formless and empty. God restored Himself through the New Creation in Christ. God restored the earth through His recreation process revealed in the first chapters of Genesis.
There is no agenda. The theory may be correct or not. If it is correct, geologists and others have an explanation for the apparent age of the earth. If it not correct, God's salvation plan through Christ is unaffected.