Of course we can mention the view point here even using Press TV as a source but it should not be stated as a fact and consequently we can't have it in infobox if press TV is the only source.   

 I think what genuinely matters more than verbatim use of the term, is whether the source characterizes the movement as being one opposed to Imperialism which Wikipedia defines as "a policy of extending a country's power and influence through colonization, use of military force, or other means". Having said that, the expert POV by PressTV does even employ the term "anti-Imperialist" verbatim to describe the Houthis. Russia Today also suggests that the struggle is part of the post-colonialist movements' struggle against imperialists and colonialists. Likewise, the author in the linked paper from Taylor & Francis identifies the same anti-imperialist themes in Hussein al-Houthi's thoughts. Furthermore beyond these sources, the very fact that Houthis' antagonists are well-known to be in alliance with the living reality of US Imperialism and the blatant reality of the ongoing war against Yemen are themselves obvious clues reaffirming the nature of the struggle by the Houthis as being anti-Imperialist in nature. Houthi leaders have also numerously stressed that they are aspiring for independence from foreign influence (namely US and Saudi) as already mentioned in the article. So I think it must be now obvious that the tag represents a definite fact, and restoration is well due.