Since Amazon is currently trading at 1.5k, if I get granted 30k in stock, I get 20 shares instead of 15, which when the stock returns to it's correct price, will now be worth 40k. I make 10k, just due to the bounce.
Now this is impacted by a lot of specifics about how your are granted stock, options, or rsus, but that's the idea.
My comment was just to the effect that GP's comment implies that belief, i.e. that their employer's current stock price is undervalued (like how AMZN is currently trading for $1.5k but is actually worth $2k).
Had they believed the stock is currently fairly priced, there's no reason to call these RSUs "cheap" or expect much excess return on them at vesting.
Worst case scenario: if they're still overvalued, then further declines can be expected, and any grant denominated by RSUs is actually worth less than its nominal cash value.
(Your current grants are only "cheap" and valuable if you expect the stock price to not only bounce back, but also go higher in the foreseeable future.)