Been a long time since I have used Beckett but their lists are by no means complete. I am not sure if this is still true but they never used to list promotional material which this may fall under in their ideas.
It will be interesting to see what value people would be willing to pay for them.
To me I see them interesting two main types of collector:
1) Master set builders — folks who want every single card from a set/series so all base, errors, variations, promos etc
2) Player collectors (and more specifically super collectors) — folks who PC a particular player and already have a large proportion of their cards so are looking for the more unusual/oddball stuff. I PC Hakeem but have such a small proportion of his cards I would be a long way from worrying about these if they mentioned him. now, say if I already had 2000+ cards and found new ones hard to come by then this would probably be interesting.
You may find guys who fit the above two categories more prevalent in the US given these booklets were not distributed in their.
Would be intriguing to see what interest there is.