Do unsynced Bitcoin ABC nodes send Bitcoin transactions instead of Bitcoin Cash transactions?
The latest version of Bitcoin ABC that is released before UAHF happened, sends Bitcoin-style transactions if it is not synced.

Proof: https://github.com/Bitcoin-ABC/bitcoin-abc/commit/fda9dab6a9fba4a95aa2d9620f28b787efccf748

The current latest version always sends Bitcoin Cash transactions.

Proof: https://github.com/Bitcoin-ABC/bitcoin-abc/blob/master/src/wallet/wallet.cpp#L2966