There was some disappointment from Western fans who fell in love with certain actors/actresses from shows 20+ years ago who were either retired, not interested, or deceased. However they did get some of their favorites (Jetman's Black Ranger), as well as a bunch of recent era cameos and tribute episodes.

From what I can tell, if they're gathering all these actors for cameos that are filmed at the same time, I bet it's for the ending sequence where the past Rangers get their keys (akin to Gokaiger's final episode credit scene).

Looks like the only actual "tribute" episodes are (gag) Samurai and Jungle Fury, because that's all we've really seen thus far in terms of actors present before the cameo filming date (Jayden, Casey)

It must be Lockes wet dream.

(I kid, i kid.)

And a Tommy episode.

From what I understand, Gokaiger getting all the returning actors that it did was in no small part effected by the horrible tsunami/earthquake/nuclear meltdown travesty that happened in the first quarter of 2011. Many actors from Super Sentai's past posted messages on social media outlets to cheer up the children of Japan, and some of them went as far as to appear in the show and movies. For them, at this horrible time, the joy of the children mattered more than their day jobs.
It also probably didn't hurt that they didn't need to be flown across the world.

On second thought, I remember reading a casting note needing TONS of extras that can wear lycra. Can't remember when filming was to happen, but it would be neat if it was for new footage of the Legend War with our returning heroes.

I'm guessing the current hiatus for Megaforce is so they can have more time to film this.

It didn't actually. Because long before the show aired they'd already gotten confirmation that a ton of actors would return. And the show did so well in fact they added more cameos as it went along. The men who played Ginga Red & Bull Black started up a twitter account after their cameo episode. They let other past actors know about the anniversary show who were unaware. And then they came out of the woodwork and contacted Toei about coming in for cameos no matter how brief they were because those actors love that franchise.

Toei added several new episodic plots revolving around past rangers because of this. In the original plan for the series, only the sentais which bestowed mecha power ups to the Gokaigers would be featured. But as a result of the actors contacting them for cameos as well as the astounding support from fans they added more and more guests.

The difference is that for Power Ranger actors they were treated like crap for the most part, by Saban and then Disney. Even if the money wasn't an issue a lot of them don't feel obligated to come back because of their bad experiences. In the case of Erin Cahill it's because the show is non-union. The US actors have legitimate concerns not to return, but Saban or possibly Tzachor are also really shafting them.

Considering the first two accessory mecha from Gokaiger are MagiDragon and PatStriker, I hope John Tui is exempt from this.
And Nic Sampson.
And Rick Medina Jr.
And the duo of Milo Cawthorne and Olivia Tennet.

Hell, THE TOYS ARE ALL FROM DISNEY'S RUN, MR. TZACHOR! You do remember Bandai is a part of production, right? They have a say and even helped Forever Red. Even if it was at the sacrifice of a badass final battle.

So what is the point of doing an anniversary series?

I'm guessing they could just skip it, it depends how they're going to run the toyline.

With RPM set in a parallel universe and SPD set in the future, they would have to jump the shark big time to fit it in.

Can't believe a year out we're in a position where most people are writing it off. Although, since Saban got the franchise back I'm struggling to give a fuck anymore. Samurai ruined Power Rangers for me, and I've watched a fair bit of operation overdrive

Time Force's cast is from a thousand years in the future. Sure we'll probably not see a single actor return, but Saban has handled a massive time difference before.