This was all blatantly deliberate. It was, IIRC, Nielsen who declared that the SOTU address required extra security measures (so they weren’t “false security concerns”; she was simply going by what had already been asserted by the security people themselves). Those specific security measures involve people who are not currently getting paid.
Not only does Pelosi get to point out to Donald that the reason he can’t have his Special Moment where and when he wants is the government shutdown he owns (and could end any time), but the message sent out by Nielsen saying that they can still provide security personnel for an event that isn’t critical to the running of the country and could easily be moved is that the Trump administration are willing to still demand the government services they want for what would be a vanity event, but everyone else suffering from the shutdown was still out of luck.
That 4D chess Trump supporters claimed he was playing? This is what it looks like.