hashkafah philosophy - Is it correct to say now “Moshiach must come in this generation”?

Is it correct to say “Moshiach must come in this generation”?

Related How do we understand Talmudic predictions of Moshiach?

The statement was made in a shiur I attended. I asked the maggid shiur how he could justify the statement. He asked me if I did not believe that Moshiach was coming. (Answer – of course I believe - Rambam's principles of faith no. 12; it's giving a time period that I worry about.) This made me doubt my thoughts which I present as a question to the community.

There seem to me to be two problems with saying now “Moshiach must come in this generation”.

One minor problem is that there is no definition of “generation”. But we could understand the Oxford English Dictionary word use

The average period, generally considered to be about thirty years, in which children grow up, become adults, and have children of their own.

So we could understand that Moshiach is to come within the next thirty years.

The other is that there is no need to believe the statement and it could be harmful.

Rambam's 12th principle is

"I believe with perfect faith in the coming of the messiah (mashiach), and though he may tarry, still I await him every day."

which places no date or time period on his coming.

Aish quotes sources that have a negative approach to attempts to calculate moshiach's arrival, The Talmud records:

Rabbi Shmuel ben Nachmani said in the name of Rabbi Yonaton: "May the spirit of those who calculate the end expire. For they say, "Since the pre-determined time has arrived, and [Moshiach] has yet to come, he will never come!" (Sanhedrin 97b)

and

Whoever forecasts the date of Moshiach's arrival has no place in the World to Come. (Derech Eretz 11)

Aish says further

We see that the Talmud is concerned about making calculations regarding the precise day for Moshiach's arrival, since errors in such calculations usually result in national disappointment, and perhaps, revelations of false messiahs.

Even the signs of Moshiach mentioned in Sotah 49b do not indicate a time period on it.

בעקבות משיחא חוצפא יסגא ויוקר יאמיר הגפן תתן פריה והיין ביוקר ומלכות תהפך למינות ואין תוכחת בית וועד יהיה לזנות והגליל יחרב והגבלן ישום ואנשי הגבול יסובבו מעיר לעיר ולא יחוננו וחכמות סופרים תסרח ויראי חטא ימאסו והאמת תהא נעדרת נערים פני זקנים ילבינו זקנים יעמדו מפני קטנים בן מנוול אב בת קמה באמה כלה בחמותה אויבי איש אנשי ביתו פני הדור כפני הכלב הבן אינו מתבייש מאביו

I asked one of my friends who replied in Yiddish די וואס ווייסט זאָגט ניט און די וואס זאָגט ווייסט ניט
Those that know don't say and those that say, don't know!