The drop problem
Demand for a drop is concentrated. A hundred people look at the same pair in the same ten minutes, and almost every message is the same question about one size. Answering by hand is how a seller loses the sale and the evening at once.
Putting sizes in the shop turns that question into a page. The buyer sees what is left, picks a size, and orders. Nobody waits for you to reply.
Set sizes as options, not as separate products
One pair, one product, sizes as options. That keeps the catalogue readable and keeps the stock count honest per size, so a size that runs out goes quiet by itself instead of taking an order you cannot fill.
Photograph the pair once and well. Side profile, sole, and one on-foot shot. Resale buyers zoom, so a sharp sole photo prevents most condition questions.
Announce in the channel, sell in the shop
Post the drop time in your channel and keep the shop button as the only way in. A link in a comment gets buried within a minute of a busy drop. The menu button never moves.
What happens after it sells out
Leave the sold-out pair visible for a day. It tells the people who missed it that the drop was real and it gives you a list of names to message when the next one lands. A shop that goes blank the moment stock runs out loses that entirely.
Write the next drop date into the shop description while attention is still on you. That single line does more for the second drop than a week of reminders later.