Due to logistical and manpower concerns, they'll be more likely to send the equipment to Poland. If they did send armour, the British would be out of armoured divisions unless they produce extras and/or send the tanks, but the British need to find the tanks first. The tanks are too important to France and the troops weren't mobilized until 23 August 1939 otl.
By the way, if the British and French did this, Poland will still fall after a week or so later than otl. And, once the Soviets invade Eastern Poland, the divisions will face having to confront the Soviets and bring them to the Axis [formally]. After the Polish Campaign, the Allies are short the armour sent to Poland.
Before August 1939, any training excuse only gives more impetus for Nazi Germany to attack earlier, especially if they send more than 1 armoured division and the divisions don't return to France by 31 August.
And, it's more likely the French troops and tanks get destroyed covering the Polish retreat, probably before the Germans reach Warsaw. Even during the retreat to the Romanian bridgehead, the same occurs to the French tanks while the Poles last a week or so longer due to German distraction and not much difference is produced compared to otl as well. Plus, the Germans still have several reserves that could compensate for the panzers fighting French tanks.