What happened
BigCommerce shipped Cornerstone 6.21.0 on July 23. The headline addition: featured-promotion callouts on product listing pages — both product cards and list view — and on the product page itself. They're controlled by a new show_featured_promotions theme setting and fed by a featured_promotions context variable, so promotions you build in the control panel can now surface right where shoppers compare products.
Backorder messaging got a real cleanup too. Backorder prompts now appear on the account order-details page for parent products and picklist options, wording lines up with what the storefront shows, and products without an explicit backorder message fall back to a store default instead of showing nothing. The 'Show backorder message' setting also now operates independently from 'Qty on Backorder.' Rounding it out, the release fixes the alignment of the shipping-expectation message on the cart page.
Why this matters
Promotions buried in a homepage banner or revealed at the cart get missed. A callout on the product card puts the offer at the exact moment a shopper is comparing your product against the next one in the grid — that's merchandising real estate stores usually pay an app subscription or a developer to get. Here it's a theme setting.
The backorder work is quieter but it's a trust play. When the storefront says one thing about a backordered item and the order-details page says another — or says nothing — you get support tickets and cancellations. Consistent wording plus a guaranteed fallback message closes that gap, which matters a lot if pre-orders or extended lead times are part of your model.
The caveat every customized Cornerstone store already knows: theme updates are where the surprises live. If your product-card or PDP templates carry custom edits, the new promotion markup may not render — or may render badly — until those changes are merged into your fork. Nothing about this release removes that tax.
What to do about it
Stage the update before it touches production
Copy your live theme, apply 6.21.0 to the copy, and preview it. Check product cards, list view, and product pages specifically — those are the templates this release modifies, and they're the ones most stores have customized. Only publish once the preview looks right.
Turn on show_featured_promotions and check the categories that matter
If you run storewide or category-level promotions, enable the setting and walk your top revenue categories to confirm the callouts render where shoppers actually browse. Promotion names are now customer-facing merchandising copy — rename anything that reads like an internal label.
Write a store-default backorder message worth showing
The fallback only helps if the default message sets real expectations. Write one that states the typical lead time and when the customer's card is charged, then audit which products carry explicit messages versus which will inherit the default.
Give the cart page a once-over after publishing
The shipping-expectation message alignment fix touches the cart template. On a customized cart, verify the message sits where it should on both desktop and mobile, and place a small test order to confirm nothing in the promotion or backorder changes disturbed the checkout handoff.