Robert Niemi's 2006 book History in the Media: Film and Television makes the claim that Dwight D. Eisenhower held a press conference to discuss historical inaccuracies in the 1965 Warner Brothers film Battle of the Bulge. It also appears in his 2013 book Inspired by True Events: An Illustrated Guide to More Than 500 History-based Films. Niemi does not elaborate beyond

So egregious were Battle's inaccuracies that former President (and WWII Supreme Allied Commander in Europe) Dwight D. Eisenhower came out of retirement for a press conference denouncing the film.

and the books do not contain footnotes, just bibliographies. Without a concrete source, mentions of the press conference thus could be regarded as anecdotal, as it certainly would have been reported on at the time. The likelihood of a press conference even happening around when it was claimed to have could also said to be low; Eisenhower suffered a severe heart attack in August of 1965 (part of a series of seven dating back to 1955, and possibly a result of a benign adrenaline-secreting adrenal gland tumor discovered after his death that could have predisposed him to heart problems), which basically ended his participation in large public affairs, but not in politics altogether. He began to have gallbladder problems in 1966, his health deteriorated (including bowel obstructions related to Crohn's disease and four heart attacks and fourteen episodes of ventricular fibrillation between April and August 1968), and he eventually died of congestive heart failure on 28 March 1969 at the age of 78.

There was interestingly two Battle of the Bulge-centered movies being produced at the same time in the mid-1960s, one by Warner Brothers and the other by Columbia Pictures. The latter, advised in part by Dwight D. Eisenhower's son John Sheldon Doud Eisenhower, never ended up being made as Warner Brothers beat them to the punch. The Columbia production had significant backing by the Department of Defense and was intended to be an "epic" and historically accurate film; Michael Anderson was to direct, Van Heflin was to star as Eisenhower, David Niven as Bernard Montgomery, John Wayne as George S. Patton, and Laurence Olivier as Adolf Hitler. Disputes arose between the production companies before either film was released. Columbia Pictures obtained an injunction against Warner Brothers, resolved by the latter not using the names of certain real people that had agreed to contribute to Columbia's film for their on-screen analogues. What resulted was a largely ahistorical movie released on 16 December 1965. A 2 December 1965 Washington Post article by film critic Richard L. Coe describes the legal fighting between the two production companies, and noted that filming for the Columbia Pictures project would begin anyway, in the fall of 1966; this never occurred, and the project died.

After the release of the Warner Brothers film, New York Times film critic Bosley Crowther lambasted it, calling it a "large, noisy, three-hour picture of some of the things that supposedly happened in the Ardennes, whipped up in color and cinema..." and deeming it "offensive" because of "evident distortion of the material and history to suit the giant Cinerama screen."

Sources I can find regarding the exact content of Richard L. Coe's article aren't exactly "academic" in nature, but the article is confirmed to exist, and was reprinted in several other newspapers shortly after it appeared in the Post. I have access to the New York Times archive through my university library (which has negative reviews of Battle of the Bulge, but does not have anything about the supposed press conference), but not the Washington Post; if anyone does, and wishes to find the content of Richard L. Coe's article, I would be grateful.

Sources:

Crowther, Bosley. "Screen: Fonda in 'Battle of the Bulge': Film Opens at Warner Cinema Theater." The New York Times (New York City, NY), December 18, 1965.

Health and Medical History of President Dwight D. Eisenhower, by John G. Sotos, M.D.

Niemi, Robert. History in the Media: Film and Television. Santa Barbara: ABC-CLIO, LLC, 2006.

Niemi, Robert. Inspired by True Events: An Illustrated Guide to More Than 500 History-based Films. Santa Barbara: ABC-CLIO, LLC, 2013.