If the ban passed, unaltered from the current form as summarized on DF's web site, I doubt you'd be limited to shotguns for very long. During the worst of times in California, a few pump-action AK rifles were made. Since they weren't semi-auto, they escaped the extra-tough state ban entirely. That wasn't enough to make them a market success since it was still possible to cobble together rifles that beat the ban (had a limited number of evil features) that were still semi-automatic. (Somebody who is looking for a tip on "future expensive collectible because it failed in the market and they only made a few" - well, you're welcome.)
The proposed ban still applies only to semi-autos. It also bans detachable magazines holding more than 10 rounds *without* grandfathering currently-owned mags. Thus, the pump-action AK would only be an answer for people willing to limit themselves to 10-round magazines (which, I assume, would immediately show up on the market in great numbers). The bullet points provided on DFs site also ban "large-capacity ammunition feeding devices" without defining that term. It's not a commonly recognized term in the shooting community so I'll have to do a little conjecture that any such device would have to be detachable, e.g. a box for linked ammo. It also refers to these items as "devices" rather than "firearms characteristics", thus no one could reasonable interpret it to mean anything other than a detachable device; any feature built into a gun that DF doesn't like simply gets listed as a design "characteristic". It wouldn't make sense to break this out into a different category unless it was intended to cover things like ammo boxes for Shrike conversions or semi-auto RPDs.
However, the current summary of the legislation specifically
exempts "manually-operated" firearms.
If the legislation passed in the form currently being promised, I reckon someone would design a "tactical" pump action rifle with a recharging slot on top for loading with stripper clips, a fixed 30-round magazine, and an optics rail forward of the action. It would resemble a fat-bellied version of a Cooper-style Scout rifle. It would also completely sidestep every provision of the ban and probably make it to market in under 30 days. If they're smart, all the big players have a team designing this rifle *right now*, just in case.
The above is only a thought experiment. It's based on summary bullet points of a bill no one has read yet since it hasn't yet been introduced. Please don't take it too seriously; there's no way whatever piece-o-crap legislation DF introduces will survive unscathed and probably no part of it will pass at all. LaPierre threw her a bone on Meet The Press for changes that would make the NICS checks more accurate but that's being ignored in the antis single-minded fixation on tools, not the people who misuse them.
Historical note: I became somewhat radicalized on the subject of "Assault Weapons" back when the original Metzenbaum assault rifle bill was introduced. (How long has that been? More than 20 years, maybe 30.) Given the inexperience of my youth, it didn't sound all that bad to me so I obtained a copy and read it. After I picked my jaw up off the floor, I realized that his "assault
rifle" bill defined the term so broadly that it would have outlawed the S&W M52 pistol that Ruby Fox used to win silver at the Los Angeles Olympics. Despite the fact that so-called "modern sporting rifles" were quite rare back in those days, the bill so broadly defined "assault rifle" that it would have outright banned most rifles, shotguns, and pistols in existence at the time. That's when I realized that these anti-gun flakes are all liars. They don't care about safety. They care about power, about getting re-elected, and about doing something to assuage their irrational fear of certain inanimate objects.
I know now to give no ground on this issue, none at all, unless I get something *big* in return. The problem is - no gun-banner has ever offered anything in return. I don't expect they ever will.