Yes, I would guess that the week following the last airdrop will be used for people to mix and match their VOUCHERs on the market to either make fractional ones whole, or sell those fractions into the market. That will also give people a chance to decide whether they want to sell their most recent airdropped VOUCHERs or use them to buy packs.
You also have to remember that there are some people who are getting thousands of VOUCHERs. Not all of them are "rich". I'm sure many of them just started playing this game early and managed to amass huge decks that all of a sudden became worth thousands of dollars. They might get 5000 or more VOUCHERs but may not want to spend $20k+ on all those packs. Who am I kidding? Of course they will! They'll have plenty of SPS with which to buy them for a discount so they can just use that.
But it IS something to keep in mind. There might be some selling of VOUCHERs into the market because I have a feeling they're going to go for a LOT more than the actual packs.