TL;DR: Only having 5 extra tiers decreases incentive to keep playing in the Mission Pass game loop. Mission Pass also said you could get all of the rewards with Extended Game Mode and it still makes you choose. Recommendation is upping total Tiers you can earn per week and just make Extended Game Mode another 30 levels.
Want to preface this all by saying I haven't hit Tier 35 yet (as it's not possible without paying), so if another 5 Tiers open up and make this post moot, then whoops.
So, I'm a little confused about this because it seems that the messaging here is off. The news article that was posted around Mission Pass says,
"If you saw a reward with multiple options and you really wanted both, don’t worry, you have another chance at it. At a certain Tier, you’ll unlock the Extended Game Mode and you’ll be able to complete the Tiers over again so you can select the rewards you didn’t take the first time."
Awesome! This is great. I've just hit level 30 and I'm looking at the "Extended Game Mode" only being 5 more levels. I like this from an in-game logic sense that weapons go to +35, so this is a neat little tie in. However, there are 14 tiers in the previous 30 that have alternate options.
In looking through these extra 5 tiers, I see that the rewards are all smashed together rather than just being repeats of the previous 14 tiers. This means not only am I missing out on tiers where instead of the outfit stuff I could've picked resources (which I was looking forward to doing in this extended game mode), but there's also some mission tiers that now have a choice between two different outfit pieces. So, I'm still making a choice between having one or the other with no way to earn ALL of the rewards from the Mission Pass.
This feels completely disingenuous when you read what the article states. It's very clear that was put in the article because there's an understanding people want to collect everything, but they way you've set it up means I still can't get everything.
I'm also surprised that the decision was made to smash these all into 5 tiers rather than stretch them out longer. As I calculated in another thread, you can earned 12.5 tiers of Mission Pass in 1 full week. With 4 weeks in a season this means there's 50 total tiers you could claim. Since 14 repeated (and technically one had three options so you really have 15), that makes a total of 45 tiers of content that could have been added. Meaning everyone that wanted to grind out all 50 tiers available would've had content to do each week.
As it stands now, I'll finish my entire Mission Pass at the end of this week and then next week the "Tier Missions" mean nothing to me because the EXP+Meseta is worthless on those missions. Most of the hardcore fan-base is still going to log in to do Dailies/Weeklies because they're "worth" it. So this really just makes the Mission Pass feel limp. Additionally, the tier with the Affix's doesn't even give you the Ex-Cube or Proton Spheres.
Personally, I would've like to have seen the "Extended Game Mode" just be doing the Mission Pass all over again and the amount of Tiers you can get per week increased to 15. This way, you could fully complete this Mission Pass twice, thus gaining all of the rewards, but you would literally have to do it every single day to not spend Star Gems on Tiers. Also, it means that you can miss two full weeks of playing and still hit your "max" level.
Look to the most popular Battle Pass in the world, Fortnite. Fortnite always has 100 Tiers in the Battle Pass and their seasons are generally 3 months (so the amount of tiers in the Mission Pass makes sense). A casual player can always get to Level 100 within a season because there's (rarely) ever any time limited missions, so you can log on toward the end and complete it. I still play fairly regularly and with 4.5 weeks left in this season, I'm already Level 100. This is a good ratio and one that would be similar to the 15 Tier per week suggestion I'm making for this. Additionally, Fortnite doesn't do a whole lot past-tier 100 for the Battle Pass purchasers, so I think PSO2 is actually doing something really cool with Extended Game Mode.
As I said, I think this is a really good idea, just kinda poorly implemented from both a sense of rewarding the most hardcore players for continuing to engage in the primary game loop for the Mission Pass, as well as feeling a little disingenuous from the original posting. Obviously, I don't think there's much that can be done for the current season other than maybe rewarding every who hits Level 35 with some of the mission cosmetics they physically can't unlock, but hopefully this can change for Season 2 to be a better system.