> [...] told The Seattle Times that the company deleted the invites from its internal calendar, [...]
It looks like the event was created on the company's internal system. You cannot expect the company to be OK with keeping this sort of stuff around. Do your organizing using tools outside of the company you're organizing against. You must expect anything pertaining to such activity to be removed swiftly and likely used against you in their fight to quell opposition.
For example, up until very recently (December 2019, when a Republican-led NLRB overturned a previous 2014 ruling) it was expressly required that employees at a company be allowed to use email in order to unionize and organize.
In fact, in general there are still quite a few protections afforded to organizing workers -- even with recent rulings. The rule is that policies cannot discriminate on content. For example, if employees are allowed to use a work Google Calendar to plan birthday parties and events, then they must be allowed to use the same calendar to unionize. If employees have a workplace bulletin board where they can post about Girl Scout cookie sales or anything else personal, then they must be allowed to use that same bulletin board to post about unionization.
You actually should not because the US has plenty of legal protections that cover the employees right to organise as well as prohibiting companies from engaging in practises that make this impossible.
I'm pretty sure this would exclude utilizing company equipment (i.e. email) for that purpose though. To illustrate: if you worked at Walmart and used their posters to make picket signs that wouldn't fly under employee rights.
But as you're helping shoehorn property rights into support for authoritarianism, I will point you to some legal advice directly:
https://www.nolo.com/legal-encyclopedia/shop-talk-rules-unio...
As long as Amazon prohibits using their calendars for all non-work content (and enforces this), they're in the right. Otherwise, this is censorship targeted at employee organizing and they're in the wrong.
The fact is; the labor force is no longer accepting what Amazon is selling as acceptable compensation. They have the right to organize amongst themselves in their common interest, and if they (Amazon) as an employer wishes to continue in safety from "unfair labor practices" (wildcat strikes etc...) I'd personally recommend they honor their obligation to allow organization to take place. Not doing so only sends the message that the office is an economic battlefield complete with victors and the vanquished; and not a workplace where good people come together to get work done, and make money in the process.
When you sacrifice your relationship with the people who work for you, I find it difficult to offer much in the way of sympathy and understanding. Especially given the last 40 year's have been marked with capital holders rolling over their laborers in myriad new ways.