I think that open Russian attack of the sort this article describes is extremely unlikely because it would carry a significant risk of destroying Russia's trade with EU and NATO nations - and that in turn would cause huge damage to Russia's economy. Such a move would also put heavy pressure on the Trump administration to adopt a more aggressive policy with regard to Russia, right at a time when Russia seems to be benefitting from the Trump administration's relative attitude of amiability towards Russia.
To be fair, the article does say:
The data suggests that Putin is preparing to attack, although alternative interpretations are possible. One can make reasoned arguments about why it would be unwise for him to attack now (or, indeed, at all).
But the title of the article strikes me as click-baity at best, deliberately propagandistic at worst: "Warning Update: Russian Preparations for Military Operations in Ukraine Continue". Of course, if you do not accept the Russian annexation of the Crimea, it makes sense to call Russian military activities in Crimea "military operations in Ukraine". But I suspect that this article's title was intentionally crafted to suggest something more than that.
A look into the article's authorship does not give me much trust in the authors' objectivity:
Kagan's brother is foreign policy analyst Robert Kagan, whose wife is Victoria Nuland, CEO of the Center for a New American Security. Frederick Kagan is married to Kimberly Kagan, president of the Institute for the Study of War.
The Institute for the Study of War (ISW) is a United States–based think tank founded in 2007 by Kimberly Kagan. ISW describes itself as a non-partisan think tank providing research and analysis regarding issues of defense and foreign affairs. Others have described ISW as "a hawkish Washington" group favoring an "aggressive foreign policy". It has produced reports on the War in Afghanistan and the Iraq War, "focusing on military operations, enemy threats, and political trends in diverse conflict zones". The non-profit organization is supported by grants and contributions from large defense contractors, including Raytheon, General Dynamics, DynCorp and others. It is headquartered in Washington, D.C.
(Wikipedia)