VIX futures prices in contango vs. backwardation

So I am having an issue with understanding how VIX futures prices change with time depending on the shape of the curve.

If the VIX futures curve is in contango, it means that longer term volatility contracts are more expensive than short term because of the higher expected LT volatility. This idea is supported by the graph 3 of the reading 16 and I am OK with this part so far.

But then, the curriculum says:" When the VIX futures curve is in contango (backwardation) and assuming volatility expectations remain unchanged, the VIX futures price will get “pulled” closer to the VIX spot price, and they will decrease (increase) in price as they approach expiration (Institute, 08/2019, p. 321)."

So in short, the as per the curriculum, in contango the VIX futures will decrease in price as they approach expiration. But, my question is, since in contango futures prices are lower than spot prices, should not they increase in order to come closer to spot value? I have no clue what I am missing here.

As you said, when the future curve is in contango prices are higher (w.r.t. to spot prices) for the longer term contracts.
If expectations remain unchanged (which is the key factor), it means that the spot price will be the same, so at times goes by the spot is unchanged therefore the future contracts that once was trading at a premium has to converge to the spot price because of no arbitrage.
Think about is as any long term future contracts is rolling down to the spot price, which is unchanged.

Hope this helps!

Yes, I was not looking at the whole thing in a proper way. Thanks.