In some cases the "new research" may involve coming across information or document that have been available for some time. It is just new to you.
Case in point: Based on the memoirs of Isaac Prall, brother of my great-grandfather, Hugh M. Prall, it was believed that their grandfather, Zachariah Rhodes was lost at sea aboard a ship named Polix &Castor. While researching at the NEHGS Library in Boston about 2006, I came across a multi-volume set entitled The Holden Family in America. The Holden Family included information on Zachariah, whose great-grandmother was Catherine Holden. The details given: Zachariah left the port of Baltimore on 14 August 1815 aboard the sloop Hannah, with his brother Perry as 1st mate. They were "never again heard from."
Here the "new research" clarified the old. Young Isaac Prall and his siblings were regaled with stories of sea captains Zachariah Rhodes and his brother-in-law, Ralph Porter and their adventures by aunt and step-mother Bathia Cunningham Porter Prall. Ships' names likely became confused over the years.
I recently posted a series on "Mary, Wife of James Wright." This is a prime example of new research replacing earlier. Early researchers named Mary Davis as wife of James Wright. In 1998-2000, Mr. Baldwin gave his case for Mrs. Wright being Mary Bowater. Most Wright descendants have accepted Mary Bowater. Some descendants of the Wrights have since, however, rebutted the Baldwin article. It's up to the Wright descendants to make their own decision on Mary's maiden name. Was it Bowater, Davis or something else?
Thirdly, there is the Matthias St. John research. Matthias, the immigrant was believed to have been born in England between 1600 and 1605. In April of 2013, J.L. Santken published an article in the NEHGS Register entitled The Origins of Mathias and Nicholas St. John Discovered. Mr. Santkin had uncovered Mathias' birth and baptism August 1601] in London. St. John/Sension/Satken records were discovered in the London Dutch Church, St. Olave, Silver Street. The family originated in Antwerp.
About the same time, Suzanne St. John proposed a Welsh Royal heritage for Matthias and Christopher/Christian, citing the same St. Olave Dutch Church records.
The argument, extremely simplified, boiled down to the definition of Strangers, as it applied to foreign refugees in London in the 16th and 17th centuries. Were Strangers those people settling in London born on the European mainland? [Dutch, French, German, Huguenot, Walloon, etc.] Or did it include those born in the British Isles born in Irish, Scots and Welsh?
Mr. Santken contended the former definition; Ms. St. John contended the Welsh were included among the Strangers. One crucial document is missing that could resolve the issue: the will of the father of Christopher/Christian St. John-Sension-Santken.
Note: I attempted to researched both sides of the argument in SLC in 2014. I was able to locate the records cited for the Dutch Churches in London and some of the Welsh records. In a casual conversation with a consultant [for another group], we briefly discussed my "problem." His comment was something to the effect of "No self-respecting Welshman would be caught dead in the Dutch Church."
Here we have two new sets of research supplanting earlier research. The question for St. John Descendants is which is correct?