There are tens of thousands of Gaelic speakers in the Lowlands. Many of them, like my kids were born here. There is absolutely no reason for them being denied services — as much as is reasonably possible at this point in time — in their native tongue.
As it so happens, where we are — not too far from Gleann Iucha — there are many — Anglicised Gaelic placenames from Duntarvie to Echline to Balerno to Dalmeny to Broxburn etc. These Gaelic names I use with my children in daily discourse. Whether or not Linlithgow was Brythonnic or Gaelic is irrelevant. The Gaelic version has been in use for centuries apparently, according to Iain Taylor.
Adding Brythonnic or Welsh (what’s it to be and how will we know? Who makes that call?) may be of some educational value. However, the underlying issue here is one of respect for Scotland’s oldest extant tongue and indeed the tongue of the Scots. Were Pictish, Norn or Brythonnic still spoken then the argument would apply to them also. To paraphrase the late Ali Abassi — it was more important to save Gaelic here than his mother tongue of Urdu as Gaelic doesn’t exist anywhere else. If it dies here, it dies.
For myself and my kids, seeing Gaelic on railway signs is natural. It’s a normal expression of any language. So, Haymarket may have been translated into Gaelic for these signs (though I’m willing to bet Edinburghs Gaels over the centuries did similar anyway), so what? Relax. It makes life more interesting. And, if you can’t pronounce it or understand, you’re free to use the English that your taxes pay for. I’m just glad that my taxes have finally got something for myself and my kids in our tongue.