If you're building it on breadboard then the stray capacitances are greater then the values required for the capacitors - so it may well work without them (simply because breadboards are rubbish!). But that doesn't mean you can leave them out in proper construction!, your breadboard layout includes them as part of the breadboard itself.
But they are an essential part of the oscillator circuit, without capacitance (either installed or stray) it won't work! - and you shouldn't recommend people to follow such faulty advice!.