Yes it does but people don't use them typically, and it's confusing to refer to that (because accounts are used by custodians or account-model crypto like Ethereum). 

And that's not the question-- sorry if it's not clear. 

Does buying "directly" to self custody mean the customer has immediate access to their Bitcoin and can send it to a cold wallet (say, a non-Foundation wallet)?

joda

bitcoin

Envoy 1.7 - Buy Bitcoin Directly to Self-custody | Foundation

foundationdvcs

Bitcoin absolutely does have accounts! Each wallet derived from a seed can use separate accounts (each with their own derivation path) to segment off funds.

You can have one seed but many "buckets" of funds to keep things segregated, i.e. KYC and no-KYC funds, business funds vs personal, etc. Both Envoy and Passport support accounts.

Accounts are a core part of the BIP 32 spec that all Bitcoin wallets use today: https://bips.dev/32/