The answer is clearly yes. I am expectant therefore I am saying thank you for that which I am expecting.
‘Expectation is the mother of manifestations’ as the saying goes.
As the scriptures says ‘as they have spoken, so i will perform’. If we grumble and continually live on grumble alley, we will the eat the fruit of it.
Isaiah 57:19 ‘I create the fruit of the lips’
If we are rejoicing and expectant, even if the exact thing you are expecting doesn’t show up, something better may be in store for which your gratitude would be well worth it.