I feel you have accepted @Oli's answer but missed its point. So here's my attempt to point out what's wrong with your answer(s) posted to that question in particular.

A disclaimer first, I was the one to cast the first delete vote on your answer (10k+ users only) which you deleted again after it was undeleted. I admit I overlooked the comment by the original asker mentioning the answer worked for them. Otherwise I would've just downvoted with a comment explaining the reason behind it. I offer my sincere apologies for that. But you did the right thing by bringing it up here at meta after the answer was deleted.

Now to the issues with the question and your answers. First of all, the question itself is not very clear. It says Wi-Fi stopped working after Ubuntu 16.04 updates, but

• says nothing about the nature of the update(s) (only "the updates that I received this morning")
• more importantly says nothing about the kernel version and the wireless device & driver being used (only laptop model is mentioned: HP Stream11)

Then your answer is essentially getting a specific version of the bcmwl-kernel-source package and installing it. But why do you think it would work when we don't even know which device OP is using? We cannot even tell whether OP has a Broadcom device at all.

_{It is not very wise to assume the device from the laptop model itself as laptop manufacturers may produce same model with different parts by different part-manufacturers depending on the model-variation, region, batch etc. In fact HP apparently ships (at least some variations of) Stream 11 laptops with Realtek RTL8723BE device instead of any Broadcom device.}

So your answer looked to me like a random shot in the dark which thankfully worked out for OP in this case (If I'm not horribly mistaken you have posted nearly identical answers to other questions which got deleted). Now imagine someone with the same laptop with a different device, but a similar-looking issue may find your answer and blindly install that specific package which most likely waste their time and energy and may cause breakage in cases (running random commands with root privilege is not a wise thing in general). As @Andrew T. puts it (in a comment posted under the deleted answer)

[...] the purpose of Stack Exchange is to build a high quality repository of Q&A as mentioned on the tour, so the goal is not only to help OP and yourself, but also future readers. Like, what is "bcmwl-kernel-source" and why it fixes the issue, etc. because this might fix OP's issue, but not other readers for this same problem.

You have had enough reputation to post a comment under the question and ask OP for more info. Alternatively, you could have added some explanation (or a caveat) to your answer following Oli's suggestion:

• What you think is going wrong
• Why you think it'll help

For example you could've added something like

If your Stream 11 comes with Broadcom <insert-device-ID> chip, then recent update to the <insert-package-name> may have broken <something>. To fix this install the <insert-package-name> package by running the following commands:
.
.

In this case the onus would be on the future reader before trying the solution as you have mentioned clearly in which case your solution is supposed to work.

But you failed to do this again, as @Zanna pointed out "you deleted your downvoted answer and reposted it verbatim".