If you watch the video there's a snippet of them digging trenches and laying barbed wire. I hardly think that would be temporary, but I've never been on a military exercise. Are you suggesting that they will do all that and then take up the barbed wire and fill the trenches back in after the exercise?
“… a multi-day exercise that will include building out defensive positions along NATO’s eastern front”
The complete sentence is : "Tanks, infantry, medics and engineers are pushing east from their base in Adazi, Latvia to take part in a multi-day exercise that will include building out defensive positions along NATO’s eastern front." (italics added for emphasis)
So, while I'd agree at first glance this could be clickbait "building out defensive positions along NATO’s eastern front" is definitely an important development IMO.
The wanton evil that russia and its people have been perpetrating in Ukraine since 2014 is unquestionably a valid reason for their exclusion. Although sporting competitions can transcend political divides and bring people closer together there is a limit to this thinking which any civilized person can distinguish.