Could be.
And somebody's gotta take a look inside to know for sure. However, most case bearing noises in other Honda models _do not_ exhibit the noise in the fashion you describe. But remember there's just too much information lost to try and accurately diagnose via the written word alone. An experienced Honda tech knows the characteristics of such a noise and the specific driving conditions that accentuate it.
Shop around for a Mom & Pop to get a comparison price. Should be priced in 3 branches unless the noise is distinctive enough and even then a good shop will caution you as to the unhappy possibilities upon disassembly.
1)Disassembly and inspection.
However, upon draining of the MT oil should any "chunks" of metal drain out its a rare occurence that its "rebuildable" cost effectively vs. replacement with a used unit. But be prepared for _small_ metallic particles. The size that will make the oil sparkle when lightly stirred.
And its this inspection step that is _important_ to correctly evaluate what's best for the customer. Rather than going ahead, against all odds, and spending your money on labor for disassembly after removal. Of course this takes experience to correctly evaluate and a good shop will be up to the job.
2)Repairs for the estimated ___________ (Trans main bearings in this situation).
This needs _some_ reasonable "wiggle" room. But must be balanced against used assembly replacement costs.
3)Repairs for complete transmission replacement (if the damage is too great to be _cost effective_ vs. the repair. You'd better verify in advance the availability and shipping time.
4)Clutch disc, pressure plate, and other related parts in the bell housing (optional unless inspection or wear indicates near failure). This is one point that owners frequently don't take advantage of. 90+% of the labor for transmission R&R applies to a clutch job. Even with a 50% worn clutch its often "cheaper" to do the repair early. Do the math and decide beforehand whether or not your going to spend a dollar now to save two in the future.
As you can see the flow for the repair has several branches. If you want the most cost effective transmission repair it won't let you down.
But don't wait too long (miles wise). What now is likely limited to bearings will cause consequential damage.
HTH!
