Will Japan Explorer Pass fare go down?

My apology if this is a silly question. I will be travelling to Tokyo next month and take a domestic flight, but I completely missed out to complete the booking when the fare was low. Today most of the flights on the day don't have the Japan Explorer Pass fare anymore, only the more expensive Japan Explorer Pass Plus.

While airlines can play around with the fare class or promotional fare, how likely it is to have the Japan Explorer Pass fare reinstated? I used to monitor some international flight fares from Japanese airlines and they didn't seem to fluctuate as often as other airlines -means when the cheaper fare class has sold out, the fare won't go down.

International fares are probably more stable while domestic fare structures are built more around early booking in my limited experience. I have a flight soon where I got a 75-day advance fare for 1/3rd of the full fare price (which was around 50,000 yen one way), and they had a limited number of those.
For your question, my answer would be no, I would not expect a promotional domestic fare to drop.

I'm assuming you are referring to this fare:

https://www.jal.co.jp/world/en/world/japan_explorer_pass/lp/

The Japan Explorer Pass is a clone of ANA's Experience Japan Fare, which ANA did away with around a year ago if I remember. JAL could stop theirs anytime they wish. If you're asking if they stop it what are the chances of them starting it up again, I'd say very unlikely. There are other discount fares offered though. ANA still has its Discover Japan Fare, which costs about 20% more, but has some limited refund capabilities if needed. They just renewed it until March, 2025.
I certainly hope JAL keeps its fare - before I flew it from Fukuoka to Sendai for just 5500 yen one way, which was a steal.

Thank you JapanCustomTour and Ken!

Yes I had checked ANA as well. ANA fare at the same promo is higher than JAL so I made my planning based on JAL, which was around 11k yen vs ANA at 15k. I recalled 3 weeks ago all the 7 flights to Hiroshima was still on this fare, but now only 2 flights remain on this fare 🥹 I was doubtful whether I should monitor if the price went down or book an alternative.

Thanks for the feedback, I booked Spring Japan flight instead. Frankly it didn't cost significantly different to JAL Explorer pass fare after factoring in Skyliner to Narita so the fare is really a steal.