Do unsynced Bitcoin ABC nodes send Bitcoin transactions instead of Bitcoin Cash transactions? Bitcoin ABC is fully compatible to Bitcoin up to the fork. Does that mean that an unsynchronized Bitcoin ABC node sends Bitcoin transactions instead of Bitcoin Cash?
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