A slippery slope fallacy occurs when one claims in the absence of any sort of evidence that a relatively small first step will inevitably lead to a chain of related steps culminating in an overall negative effect.
It is not a fallacy when one can provide evidence for or otherwise demonstrate that progression.
What you believe you can provide as evidence that demonstrating an inevitable progression is merely a nebulous narrative being passed as evidence. The existence of gun regulations in most every country of the world, including our own, actually demonstrates the opposite. Regulations can be unoppressive and adaptable to local circumstances. IOW What America already has regarding gun regulations are proof that regulations do not inevitably result in the complete loss of the ability to own guns responsibly.
I actually provided the link with Biden's policy proposals. So yes, I'm aware of them. I happen to agree with the majority of Democrats and Republicans that we can improve upon the regulations we currently have.