Flyback Transformer -- RC Snubber vs. TVS Diode?
Without a schematic, it is difficult to judge. A \$RC\$ snubber is different than an \$RC\$ damper. What is possible is to have the parallel combination of a damper and a TVS as shown below:



The \$RC\$ network is there to damp the resonance of the leakage inductance and the capacitance lumped at the drain node. Sometimes, the leakage contribution is so energetic that when the TVS series diode blocks, the ringing on the drain can go below ground and forward-bias the MOSFET body diode. Not a big deal with a discrete MOSFET but it can inject carriers into the substrate if we talk about a switcher featuring a lateral FET. By dissipating energy, the \$RC\$ network will damp the resonance and keep the leakage ringing under control. Reverse-bias of CMOS-based switchers are a cause of destruction and must be avoided.

A TVS is a) an expensive device (compared to a classical \$RCD\$ peak clamp and b) it radiates a significant amount of energy as the leakage inductance reset time is very small. For all of these reasons, TVS are rarely used in commercial products. However, again, if you have a switcher with an integrated FET, as its body diode is lightly doped, it cannot accept accidental avalanche and a hard clamp is truly needed, hence the TVS presence. Please keep in mind that beside delivering power at nominal input, these power supplies (at least for quality models) have to go through numerous input surges tests and must survive them. Sometimes, protection components that look superfluous are there to pass these tests and keep silent for most of the time. I would not remove them : )