question about locktdown state

[yamt]

the explainer says:

Components prevent unexpected reentrance by setting the "lockdown" state (in the previous bullet) whenever calling out through an import, clearing the lockdown state on return, thereby preventing reentrant export calls in the interim. This establishes a clear contract between separate components that both prevents obscure composition-time bugs and also enables more-efficient non-reentrant runtime glue code (particularly in the middle of the Canonical ABI). This implies that components by default don't allow concurrency and multi-threaded access will trap.

does it mean to prevent callback-style api as well?