As of GraphQL API version 2025-10, we have introduced a new value, PRESERVE_STANDALONE_VARIANT, to the ProductVariantsBulkCreateStrategy. This value can be used as an optional argument in the productVariantsBulkCreate mutation.
This is a companion discussion topic for the original entry at https://shopify.dev/changelog/new-preservestandalonevariant-strategy-for-productvariantsbulkcreate-mutation