MPs could certainly be forgiven—if it's my business to forgive anyone—for not knowing that these plans are unfunded, because they have the trappings of a funded plan. As you pointed out, you're paying contributions, and if you look at the financial statements for the plans, there appears to be an asset against the actuarial liability that's based on how long MPs are likely to live, how much income will be replaced and so on.
The awkward fact is that the MPs' plan is still like the pre-2000 plans for the public service, for the RCMP and for the Canadian Forces. Those contributions are not buying assets. They are simply going essentially into the government's current cash flow. The payment for the pensions is coming out of the government's current cash flow.
That's unfortunate. People like to talk these days, for good reason, about tone at the top. It's awkward that the federal members of Parliament do not participate in a pension plan that is appropriately funded. It also provides a key lesson in the problem you have when the financial statements do not report in a way that ordinary people—non-experts and non-actuaries—can understand when they are wondering whether their pension is properly backed or not, or if a taxpayer is looking at the federal government's finances and asking, “Am I on the hook for something here that I didn't know about?”
I'll elaborate briefly in case you want to follow this up. The chief actuary does reports on the federal MPs' pension plan. You'll see a line in it that says there is no separate fund held in these plans. The accounts are simply bookkeeping entries, and I regret to tell you there's no money in them.