Question about calendar spreads assignment risk

[taowave]

Read much??

https://www.fidelity.com/learning-c...ons-strategy-guide/long-calendar-spread-calls

 

[cesfx]

butterfly has capped upside and downside.
for calendars, feel free to sell front month and buy back month to see that you have unlimited risk

Even the fidelity link explains clearly that long calendars max risk is the cost of the spread. At least until front month exp.
At the centre it might look like a short straddle, but I see no unlimited risk.