I think Lyrian is probably on the money with the expedition wall. I'm not convinced how severe the wall is though. I'm already over 120 relics with 4 days to go (no lapis spent of course, though I did spend 2 coins to refresh). I'll have to fail a lot of missions if I want to avoid the moogle now.
The drain on money is also real, but spread over enough time that it's pretty easy to keep ahead I think. 10mil is no small amount, but if it's over six months it's a lot more doable.
Rather than push people to get the moogle at all, I think Gumi want people to have to choose between the moogle and the nicer rewards. You can stick with the boring c-rank ones that give useless magicite to practically guarantee the 160, or you can go for the risky but very tempting giancrysts and fail half the time.
One issue though that Gumi failed to handle: If you're TM farming 24/7 then you don't care if an expedition cuts off your best team. You're only running 5 low-level characters anyway. That means you have at least one really good squad you can send off on your hardest mission. Sure there's still no guarantee of success but it saves you another 5 characters worth of equipment and slots and whatnot. That, plus the expeditions don't even award TM progress. We can continue to speculate what Gumi's overall agenda is here but I think it's safe to say expeditions were not their answer to TM farming after all.
Another thought: do we have any guarantee the rewards for relics gathered won't change weekly? Maybe this is a first week thing to get people hooked and next time we'll just get megacites or something.
Oh hey, got some friend slots open if anyone still hasn't added me. 911,468,888. I'm fielding a 915atk Orlandu with dark element and double manslayer for the Maxwell trial, but I'll probably switch back to Maxwell herself for the rest of the week soon.